[patch 00/17] paravirt_ops updates

[patch 00/17] paravirt_ops updates

[Jeremy Fitzhardinge]

Hi Andi,

This series of patches updates paravirt_ops in various ways.  Some of the
changes are plain cleanups and improvements, and some add some interfaces
necessary for Xen.

The brief overview:

add-MAINTAINERS.patch			- obvious
remove-CONFIG_DEBUG_PARAVIRT.patch	- no longer needed
paravirt-nop.patch			- mark nop operations consistently
paravirt-pte-accessors.patch		- operations to pack/unpack ptes
paravirt-memory-init.patch		- hooks for memory/pagetable init
paravirt-fixmap.patch			- add fixmap for paravirt boot
shared-kernel-pmd.patch			- allow selectable shared kernel pmd
mm-lifetime-hooks.patch			- hooks for mm dup/activate/exit
paravirt-patch-rename-paravirt_patch.patch - rename patch structure for clarity
paravirt-use-offset-site-ids.patch	- use patch-site id derived from offset
paravirt-fix-clobbers.patch		- fix register clobbers for patch sites
paravirt-patchable-call-wrappers.patch	- wrap paravirt calls for patching
paravirt-patch-machinery.patch		- common patch machinery
paravirt-flush_tlb_others.patch		- paravirt hook for cross-cpu tlb flushing
revert-map_pt_hook.patch		- back out map_pt_hook
paravirt-kmap_atomic_pte.patch		- add kmap_atomic_pte for highpte
paravirt-sched-clock.patch		- hook to measure schedulable time

Thanks,
	J

-- 

[patch 00/17] paravirt_ops updates

[Jeremy Fitzhardinge]

Hi Andi,

This series of patches updates paravirt_ops in various ways.  Some of the
changes are plain cleanups and improvements, and some add some interfaces
necessary for Xen.

The brief overview:

add-MAINTAINERS.patch			- obvious
remove-CONFIG_DEBUG_PARAVIRT.patch	- no longer needed
paravirt-nop.patch			- mark nop operations consistently
paravirt-pte-accessors.patch		- operations to pack/unpack ptes
paravirt-memory-init.patch		- hooks for memory/pagetable init
paravirt-fixmap.patch			- add fixmap for paravirt boot
shared-kernel-pmd.patch			- allow selectable shared kernel pmd
mm-lifetime-hooks.patch			- hooks for mm dup/activate/exit
paravirt-patch-rename-paravirt_patch.patch - rename patch structure for clarity
paravirt-use-offset-site-ids.patch	- use patch-site id derived from offset
paravirt-fix-clobbers.patch		- fix register clobbers for patch sites
paravirt-patchable-call-wrappers.patch	- wrap paravirt calls for patching
paravirt-patch-machinery.patch		- common patch machinery
paravirt-flush_tlb_others.patch		- paravirt hook for cross-cpu tlb flushing
revert-map_pt_hook.patch		- back out map_pt_hook
paravirt-kmap_atomic_pte.patch		- add kmap_atomic_pte for highpte
paravirt-sched-clock.patch		- hook to measure schedulable time

Thanks,
	J

-- 

[patch 01/17] update MAINTAINERS

[Jeremy Fitzhardinge]

[-- Attachment #1: add-MAINTAINERS.patch --]
[-- Type: text/plain, Size: 1227 bytes --]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
---
 MAINTAINERS |   22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

===================================================================
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2583,6 +2583,19 @@ T:	cvs cvs.parisc-linux.org:/var/cvs/lin
 T:	cvs cvs.parisc-linux.org:/var/cvs/linux-2.6
 S:	Maintained
 
+PARAVIRT_OPS INTERFACE
+P:	Jeremy Fitzhardinge
+M:	jeremy@xensource.com
+P:	Chris Wright
+M:	chrisw@sous-sol.org
+P:	Zachary Amsden
+M:	zach@vmware.com
+P:	Rusty Russell
+M:	rusty@rustcorp.com.au
+L:	virtualization@lists.osdl.org
+L:	linux-kernel@vger.kernel.org
+S:	Supported
+
 PC87360 HARDWARE MONITORING DRIVER
 P:	Jim Cromie
 M:	jim.cromie@gmail.com
@@ -3780,6 +3793,15 @@ L:	linux-x25@vger.kernel.org
 L:	linux-x25@vger.kernel.org
 S:	Maintained
 
+XEN HYPERVISOR INTERFACE
+P:	Jeremy Fitzhardinge
+M:	jeremy@xensource.com
+P:	Chris Wright
+M:	chrisw@sous-sol.org
+L:	virtualization@lists.osdl.org
+L:	xen-devel@lists.xensource.com
+S:	Supported
+
 XFS FILESYSTEM
 P:	Silicon Graphics Inc
 P:	Tim Shimmin, David Chatterton

-- 

[patch 02/17] Remove CONFIG_DEBUG_PARAVIRT

[Jeremy Fitzhardinge]

[-- Attachment #1: remove-CONFIG_DEBUG_PARAVIRT.patch --]
[-- Type: text/plain, Size: 2004 bytes --]

Remove CONFIG_DEBUG_PARAVIRT.  When inlining code, this option
attempts to trash registers in the patch-site's "clobber" field, on
the grounds that this should find bugs with incorrect clobbers.
Unfortunately, the clobber field really means "registers modified by
this patch site", which includes return values.

Because of this, this option has outlived its usefulness, so remove
it.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>

---
 arch/i386/Kconfig.debug        |   10 ----------
 arch/i386/kernel/alternative.c |   14 +-------------
 2 files changed, 1 insertion(+), 23 deletions(-)

===================================================================
--- a/arch/i386/Kconfig.debug
+++ b/arch/i386/Kconfig.debug
@@ -85,14 +85,4 @@ config DOUBLEFAULT
           option saves about 4k and might cause you much additional grey
           hair.
 
-config DEBUG_PARAVIRT
-	bool "Enable some paravirtualization debugging"
-	default n
-	depends on PARAVIRT && DEBUG_KERNEL
-	help
-	  Currently deliberately clobbers regs which are allowed to be
-	  clobbered in inlined paravirt hooks, even in native mode.
-	  If turning this off solves a problem, then DISABLE_INTERRUPTS() or
-	  ENABLE_INTERRUPTS() is lying about what registers can be clobbered.
-
 endmenu
===================================================================
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -359,19 +359,7 @@ void apply_paravirt(struct paravirt_patc
 
 		used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
 					  p->len);
-#ifdef CONFIG_DEBUG_PARAVIRT
-		{
-		int i;
-		/* Deliberately clobber regs using "not %reg" to find bugs. */
-		for (i = 0; i < 3; i++) {
-			if (p->len - used >= 2 && (p->clobbers & (1 << i))) {
-				memcpy(p->instr + used, "\xf7\xd0", 2);
-				p->instr[used+1] |= i;
-				used += 2;
-			}
-		}
-		}
-#endif
+
 		/* Pad the rest with nops */
 		nop_out(p->instr + used, p->len - used);
 	}

-- 

[patch 03/17] use paravirt_nop to consistently mark no-op operations

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-nop.patch --]
[-- Type: text/plain, Size: 3283 bytes --]

Add a _paravirt_nop function for use as a stub for no-op operations,
and paravirt_nop #defined void * version to make using it easier
(since all its uses are as a void *).

This is useful to allow the patcher to automatically identify noop
operations so it can simply nop out the callsite.


Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
[mingo] but only as a cleanup of the current open-coded (void *) casts.
My problem with this is that it loses the types. Not that there is much
to check for, but still, this adds some assumptions about how function
calls look like

---
 arch/i386/kernel/paravirt.c |   26 +++++++++++++-------------
 include/asm-i386/paravirt.h |    3 +++
 2 files changed, 16 insertions(+), 13 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -35,7 +35,7 @@
 #include <asm/timer.h>
 
 /* nop stub */
-static void native_nop(void)
+void _paravirt_nop(void)
 {
 }
 
@@ -490,7 +490,7 @@ struct paravirt_ops paravirt_ops = {
 
  	.patch = native_patch,
 	.banner = default_banner,
-	.arch_setup = native_nop,
+	.arch_setup = paravirt_nop,
 	.memory_setup = machine_specific_memory_setup,
 	.get_wallclock = native_get_wallclock,
 	.set_wallclock = native_set_wallclock,
@@ -546,25 +546,25 @@ struct paravirt_ops paravirt_ops = {
 	.setup_boot_clock = setup_boot_APIC_clock,
 	.setup_secondary_clock = setup_secondary_APIC_clock,
 #endif
-	.set_lazy_mode = (void *)native_nop,
+	.set_lazy_mode = paravirt_nop,
 
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
 
-	.map_pt_hook = (void *)native_nop,
-
-	.alloc_pt = (void *)native_nop,
-	.alloc_pd = (void *)native_nop,
-	.alloc_pd_clone = (void *)native_nop,
-	.release_pt = (void *)native_nop,
-	.release_pd = (void *)native_nop,
+	.map_pt_hook = paravirt_nop,
+
+	.alloc_pt = paravirt_nop,
+	.alloc_pd = paravirt_nop,
+	.alloc_pd_clone = paravirt_nop,
+	.release_pt = paravirt_nop,
+	.release_pd = paravirt_nop,
 
 	.set_pte = native_set_pte,
 	.set_pte_at = native_set_pte_at,
 	.set_pmd = native_set_pmd,
-	.pte_update = (void *)native_nop,
-	.pte_update_defer = (void *)native_nop,
+	.pte_update = paravirt_nop,
+	.pte_update_defer = paravirt_nop,
 #ifdef CONFIG_X86_PAE
 	.set_pte_atomic = native_set_pte_atomic,
 	.set_pte_present = native_set_pte_present,
@@ -576,7 +576,7 @@ struct paravirt_ops paravirt_ops = {
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
 
-	.startup_ipi_hook = (void *)native_nop,
+	.startup_ipi_hook = paravirt_nop,
 };
 
 /*
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -430,6 +430,9 @@ static inline void pmd_clear(pmd_t *pmdp
 #define arch_enter_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_MMU)
 #define arch_leave_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)
 
+void _paravirt_nop(void);
+#define paravirt_nop	((void *)_paravirt_nop)
+
 /* These all sit in the .parainstructions section to tell us what to patch. */
 struct paravirt_patch {
 	u8 *instr; 		/* original instructions */

-- 

[patch 03/17] use paravirt_nop to consistently mark no-op operations

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-nop.patch --]
[-- Type: text/plain, Size: 3381 bytes --]

Add a _paravirt_nop function for use as a stub for no-op operations,
and paravirt_nop #defined void * version to make using it easier
(since all its uses are as a void *).

This is useful to allow the patcher to automatically identify noop
operations so it can simply nop out the callsite.


Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
[mingo] but only as a cleanup of the current open-coded (void *) casts.
My problem with this is that it loses the types. Not that there is much
to check for, but still, this adds some assumptions about how function
calls look like

---
 arch/i386/kernel/paravirt.c |   26 +++++++++++++-------------
 include/asm-i386/paravirt.h |    3 +++
 2 files changed, 16 insertions(+), 13 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -35,7 +35,7 @@
 #include <asm/timer.h>
 
 /* nop stub */
-static void native_nop(void)
+void _paravirt_nop(void)
 {
 }
 
@@ -490,7 +490,7 @@ struct paravirt_ops paravirt_ops = {
 
  	.patch = native_patch,
 	.banner = default_banner,
-	.arch_setup = native_nop,
+	.arch_setup = paravirt_nop,
 	.memory_setup = machine_specific_memory_setup,
 	.get_wallclock = native_get_wallclock,
 	.set_wallclock = native_set_wallclock,
@@ -546,25 +546,25 @@ struct paravirt_ops paravirt_ops = {
 	.setup_boot_clock = setup_boot_APIC_clock,
 	.setup_secondary_clock = setup_secondary_APIC_clock,
 #endif
-	.set_lazy_mode = (void *)native_nop,
+	.set_lazy_mode = paravirt_nop,
 
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
 
-	.map_pt_hook = (void *)native_nop,
-
-	.alloc_pt = (void *)native_nop,
-	.alloc_pd = (void *)native_nop,
-	.alloc_pd_clone = (void *)native_nop,
-	.release_pt = (void *)native_nop,
-	.release_pd = (void *)native_nop,
+	.map_pt_hook = paravirt_nop,
+
+	.alloc_pt = paravirt_nop,
+	.alloc_pd = paravirt_nop,
+	.alloc_pd_clone = paravirt_nop,
+	.release_pt = paravirt_nop,
+	.release_pd = paravirt_nop,
 
 	.set_pte = native_set_pte,
 	.set_pte_at = native_set_pte_at,
 	.set_pmd = native_set_pmd,
-	.pte_update = (void *)native_nop,
-	.pte_update_defer = (void *)native_nop,
+	.pte_update = paravirt_nop,
+	.pte_update_defer = paravirt_nop,
 #ifdef CONFIG_X86_PAE
 	.set_pte_atomic = native_set_pte_atomic,
 	.set_pte_present = native_set_pte_present,
@@ -576,7 +576,7 @@ struct paravirt_ops paravirt_ops = {
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
 
-	.startup_ipi_hook = (void *)native_nop,
+	.startup_ipi_hook = paravirt_nop,
 };
 
 /*
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -430,6 +430,9 @@ static inline void pmd_clear(pmd_t *pmdp
 #define arch_enter_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_MMU)
 #define arch_leave_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)
 
+void _paravirt_nop(void);
+#define paravirt_nop	((void *)_paravirt_nop)
+
 /* These all sit in the .parainstructions section to tell us what to patch. */
 struct paravirt_patch {
 	u8 *instr; 		/* original instructions */

-- 

[patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-pte-accessors.patch --]
[-- Type: text/plain, Size: 18893 bytes --]

Add a set of accessors to pack, unpack and modify page table entries
(at all levels).  This allows a paravirt implementation to control the
contents of pgd/pmd/pte entries.  For example, Xen uses this to
convert the (pseudo-)physical address into a machine address when
populating a pagetable entry, and converting back to pphys address
when an entry is read.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c       |   84 +++++--------------------------------
 arch/i386/kernel/vmi.c            |    6 +-
 include/asm-i386/page.h           |   79 +++++++++++++++++++++++++++++-----
 include/asm-i386/paravirt.h       |   52 +++++++++++++++++-----
 include/asm-i386/pgtable-2level.h |   28 +++++++++---
 include/asm-i386/pgtable-3level.h |   65 +++++++++++++++++-----------
 include/asm-i386/pgtable.h        |    2 
 7 files changed, 186 insertions(+), 130 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -399,78 +399,6 @@ static void native_flush_tlb_single(u32 
 {
 	__native_flush_tlb_single(addr);
 }
-
-#ifndef CONFIG_X86_PAE
-static void native_set_pte(pte_t *ptep, pte_t pteval)
-{
-	*ptep = pteval;
-}
-
-static void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
-{
-	*ptep = pteval;
-}
-
-static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
-	*pmdp = pmdval;
-}
-
-#else /* CONFIG_X86_PAE */
-
-static void native_set_pte(pte_t *ptep, pte_t pte)
-{
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte)
-{
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
-{
-	ptep->pte_low = 0;
-	smp_wmb();
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_atomic(pte_t *ptep, pte_t pteval)
-{
-	set_64bit((unsigned long long *)ptep,pte_val(pteval));
-}
-
-static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
-	set_64bit((unsigned long long *)pmdp,pmd_val(pmdval));
-}
-
-static void native_set_pud(pud_t *pudp, pud_t pudval)
-{
-	*pudp = pudval;
-}
-
-static void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
-{
-	ptep->pte_low = 0;
-	smp_wmb();
-	ptep->pte_high = 0;
-}
-
-static void native_pmd_clear(pmd_t *pmd)
-{
-	u32 *tmp = (u32 *)pmd;
-	*tmp = 0;
-	smp_wmb();
-	*(tmp + 1) = 0;
-}
-#endif /* CONFIG_X86_PAE */
 
 /* These are in entry.S */
 extern void native_iret(void);
@@ -565,13 +493,25 @@ struct paravirt_ops paravirt_ops = {
 	.set_pmd = native_set_pmd,
 	.pte_update = paravirt_nop,
 	.pte_update_defer = paravirt_nop,
+
+	.ptep_get_and_clear = native_ptep_get_and_clear,
+
 #ifdef CONFIG_X86_PAE
 	.set_pte_atomic = native_set_pte_atomic,
 	.set_pte_present = native_set_pte_present,
 	.set_pud = native_set_pud,
 	.pte_clear = native_pte_clear,
 	.pmd_clear = native_pmd_clear,
+
+	.pmd_val = native_pmd_val,
+	.make_pmd = native_make_pmd,
 #endif
+
+	.pte_val = native_pte_val,
+	.pgd_val = native_pgd_val,
+
+	.make_pte = native_make_pte,
+	.make_pgd = native_make_pgd,
 
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -444,13 +444,13 @@ static void vmi_release_pd(u32 pfn)
         ((level) | (is_current_as(mm, user) ?                           \
                 (VMI_PAGE_DEFER | VMI_PAGE_CURRENT_AS | ((addr) & VMI_PAGE_VA_MASK)) : 0))
 
-static void vmi_update_pte(struct mm_struct *mm, u32 addr, pte_t *ptep)
+static void vmi_update_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.update_pte(ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
 }
 
-static void vmi_update_pte_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
+static void vmi_update_pte_defer(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.update_pte(ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 0));
@@ -463,7 +463,7 @@ static void vmi_set_pte(pte_t *ptep, pte
 	vmi_ops.set_pte(pte, ptep, VMI_PAGE_PT);
 }
 
-static void vmi_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte)
+static void vmi_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
===================================================================
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -12,7 +12,6 @@
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
-
 #ifdef CONFIG_X86_USE_3DNOW
 
 #include <asm/mmx.h>
@@ -42,26 +41,81 @@
  * These are used to make use of C type-checking..
  */
 extern int nx_enabled;
+
 #ifdef CONFIG_X86_PAE
 extern unsigned long long __supported_pte_mask;
 typedef struct { unsigned long pte_low, pte_high; } pte_t;
 typedef struct { unsigned long long pmd; } pmd_t;
 typedef struct { unsigned long long pgd; } pgd_t;
 typedef struct { unsigned long long pgprot; } pgprot_t;
-#define pmd_val(x)	((x).pmd)
-#define pte_val(x)	((x).pte_low | ((unsigned long long)(x).pte_high << 32))
-#define __pmd(x) ((pmd_t) { (x) } )
+
+static inline unsigned long long native_pgd_val(pgd_t pgd)
+{
+	return pgd.pgd;
+}
+
+static inline unsigned long long native_pmd_val(pmd_t pmd)
+{
+	return pmd.pmd;
+}
+
+static inline unsigned long long native_pte_val(pte_t pte)
+{
+	return pte.pte_low | ((unsigned long long)pte.pte_high << 32);
+}
+
+static inline pgd_t native_make_pgd(unsigned long long val)
+{
+	return (pgd_t) { val };
+}
+
+static inline pmd_t native_make_pmd(unsigned long long val)
+{
+	return (pmd_t) { val };
+}
+
+static inline pte_t native_make_pte(unsigned long long val)
+{
+	return (pte_t) { .pte_low = val, .pte_high = (val >> 32) } ;
+}
+
+#ifndef CONFIG_PARAVIRT
+#define pmd_val(x)	native_pmd_val(x)
+#define __pmd(x)	native_make_pmd(x)
+#endif
+
 #define HPAGE_SHIFT	21
 #include <asm-generic/pgtable-nopud.h>
-#else
+#else  /* !CONFIG_X86_PAE */
 typedef struct { unsigned long pte_low; } pte_t;
 typedef struct { unsigned long pgd; } pgd_t;
 typedef struct { unsigned long pgprot; } pgprot_t;
 #define boot_pte_t pte_t /* or would you rather have a typedef */
-#define pte_val(x)	((x).pte_low)
+
+static inline unsigned long native_pgd_val(pgd_t pgd)
+{
+	return pgd.pgd;
+}
+
+static inline unsigned long native_pte_val(pte_t pte)
+{
+	return pte.pte_low;
+}
+
+static inline pgd_t native_make_pgd(unsigned long val)
+{
+	return (pgd_t) { val };
+}
+
+static inline pte_t native_make_pte(unsigned long val)
+{
+	return (pte_t) { .pte_low = val };
+}
+
 #define HPAGE_SHIFT	22
 #include <asm-generic/pgtable-nopmd.h>
-#endif
+#endif	/* CONFIG_X86_PAE */
+
 #define PTE_MASK	PAGE_MASK
 
 #ifdef CONFIG_HUGETLB_PAGE
@@ -71,12 +125,15 @@ typedef struct { unsigned long pgprot; }
 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 #endif
 
-#define pgd_val(x)	((x).pgd)
 #define pgprot_val(x)	((x).pgprot)
-
-#define __pte(x) ((pte_t) { (x) } )
-#define __pgd(x) ((pgd_t) { (x) } )
 #define __pgprot(x)	((pgprot_t) { (x) } )
+
+#ifndef CONFIG_PARAVIRT
+#define pgd_val(x)	native_pgd_val(x)
+#define __pgd(x)	native_make_pgd(x)
+#define pte_val(x)	native_pte_val(x)
+#define __pte(x)	native_make_pte(x)
+#endif
 
 #endif /* !__ASSEMBLY__ */
 
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -2,7 +2,6 @@
 #define __ASM_PARAVIRT_H
 /* Various instructions on x86 need to be replaced for
  * para-virtualization: those hooks are defined here. */
-#include <linux/linkage.h>
 #include <linux/stringify.h>
 #include <asm/page.h>
 
@@ -25,6 +24,8 @@
 #define CLBR_ANY 0x7
 
 #ifndef __ASSEMBLY__
+#include <linux/types.h>
+
 struct thread_struct;
 struct Xgt_desc_struct;
 struct tss_struct;
@@ -53,11 +54,6 @@ struct paravirt_ops
 	unsigned long (*get_wallclock)(void);
 	int (*set_wallclock)(unsigned long);
 	void (*time_init)(void);
-
-	/* All the function pointers here are declared as "fastcall"
-	   so that we get a specific register-based calling
-	   convention.  This makes it easier to implement inline
-	   assembler replacements. */
 
 	void (*cpuid)(unsigned int *eax, unsigned int *ebx,
 		      unsigned int *ecx, unsigned int *edx);
@@ -139,16 +135,33 @@ struct paravirt_ops
 	void (*release_pd)(u32 pfn);
 
 	void (*set_pte)(pte_t *ptep, pte_t pteval);
-	void (*set_pte_at)(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval);
+	void (*set_pte_at)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval);
 	void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
-	void (*pte_update)(struct mm_struct *mm, u32 addr, pte_t *ptep);
-	void (*pte_update_defer)(struct mm_struct *mm, u32 addr, pte_t *ptep);
+	void (*pte_update)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+	void (*pte_update_defer)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+
+ 	pte_t (*ptep_get_and_clear)(pte_t *ptep);
+
 #ifdef CONFIG_X86_PAE
 	void (*set_pte_atomic)(pte_t *ptep, pte_t pteval);
-	void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
+ 	void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
 	void (*set_pud)(pud_t *pudp, pud_t pudval);
-	void (*pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+ 	void (*pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 	void (*pmd_clear)(pmd_t *pmdp);
+
+	unsigned long long (*pte_val)(pte_t);
+	unsigned long long (*pmd_val)(pmd_t);
+	unsigned long long (*pgd_val)(pgd_t);
+
+	pte_t (*make_pte)(unsigned long long pte);
+	pmd_t (*make_pmd)(unsigned long long pmd);
+	pgd_t (*make_pgd)(unsigned long long pgd);
+#else
+	unsigned long (*pte_val)(pte_t);
+	unsigned long (*pgd_val)(pgd_t);
+
+	pte_t (*make_pte)(unsigned long pte);
+	pgd_t (*make_pgd)(unsigned long pgd);
 #endif
 
 	void (*set_lazy_mode)(int mode);
@@ -218,6 +231,8 @@ static inline void __cpuid(unsigned int 
 #define read_cr4() paravirt_ops.read_cr4()
 #define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
 #define write_cr4(x) paravirt_ops.write_cr4(x)
+
+#define raw_ptep_get_and_clear(xp)	(paravirt_ops.ptep_get_and_clear(xp))
 
 static inline void raw_safe_halt(void)
 {
@@ -303,6 +318,17 @@ static inline void halt(void)
 	(paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
 #define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
 
+#define __pte(x)	paravirt_ops.make_pte(x)
+#define __pgd(x)	paravirt_ops.make_pgd(x)
+
+#define pte_val(x)	paravirt_ops.pte_val(x)
+#define pgd_val(x)	paravirt_ops.pgd_val(x)
+
+#ifdef CONFIG_X86_PAE
+#define __pmd(x)	paravirt_ops.make_pmd(x)
+#define pmd_val(x)	paravirt_ops.pmd_val(x)
+#endif
+
 /* The paravirtualized I/O functions */
 static inline void slow_down_io(void) {
 	paravirt_ops.io_delay();
@@ -343,6 +369,7 @@ static inline void setup_secondary_clock
 }
 #endif
 
+
 #ifdef CONFIG_SMP
 static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
 				    unsigned long start_esp)
@@ -370,7 +397,8 @@ static inline void set_pte(pte_t *ptep, 
 	paravirt_ops.set_pte(ptep, pteval);
 }
 
-static inline void set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval)
 {
 	paravirt_ops.set_pte_at(mm, addr, ptep, pteval);
 }
===================================================================
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -11,11 +11,24 @@
  * within a page table are directly modified.  Thus, the following
  * hook is made available.
  */
+static inline void native_set_pte(pte_t *ptep , pte_t pte)
+{
+	*ptep = pte;
+}
+static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep , pte_t pte)
+{
+	native_set_pte(ptep, pte);
+}
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+	*pmdp = pmd;
+}
 #ifndef CONFIG_PARAVIRT
-#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
-#endif
+#define set_pte(pteptr, pteval)		native_set_pte(pteptr, pteval)
+#define set_pte_at(mm,addr,ptep,pteval) native_set_pte_at(mm, addr, ptep, pteval)
+#define set_pmd(pmdptr, pmdval)		native_set_pmd(pmdptr, pmdval)
+#endif
 
 #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
 #define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval)
@@ -23,11 +36,14 @@
 #define pte_clear(mm,addr,xp)	do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
 #define pmd_clear(xp)	do { set_pmd(xp, __pmd(0)); } while (0)
 
-#define raw_ptep_get_and_clear(xp)	__pte(xchg(&(xp)->pte_low, 0))
+static inline pte_t native_ptep_get_and_clear(pte_t *xp)
+{
+	return __pte(xchg(&xp->pte_low, 0));
+}
 
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
 #define pte_none(x)		(!(x).pte_low)
-#define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
+#define pte_pfn(x)		(pte_val(x) >> PAGE_SHIFT)
 #define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 #define pfn_pmd(pfn, prot)	__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 
===================================================================
--- a/include/asm-i386/pgtable-3level.h
+++ b/include/asm-i386/pgtable-3level.h
@@ -42,20 +42,23 @@ static inline int pte_exec_kernel(pte_t 
 	return pte_x(pte);
 }
 
-#ifndef CONFIG_PARAVIRT
 /* Rules for using set_pte: the pte being assigned *must* be
  * either not present or in a state where the hardware will
  * not attempt to update the pte.  In places where this is
  * not possible, use pte_get_and_clear to obtain the old pte
  * value and then use set_pte to update it.  -ben
  */
-static inline void set_pte(pte_t *ptep, pte_t pte)
+static inline void native_set_pte(pte_t *ptep, pte_t pte)
 {
 	ptep->pte_high = pte.pte_high;
 	smp_wmb();
 	ptep->pte_low = pte.pte_low;
 }
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep , pte_t pte)
+{
+	native_set_pte(ptep, pte);
+}
 
 /*
  * Since this is only called on user PTEs, and the page fault handler
@@ -63,7 +66,8 @@ static inline void set_pte(pte_t *ptep, 
  * we are justified in merely clearing the PTE present bit, followed
  * by a set.  The ordering here is important.
  */
-static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+static inline void native_set_pte_present(struct mm_struct *mm, unsigned long addr,
+					  pte_t *ptep, pte_t pte)
 {
 	ptep->pte_low = 0;
 	smp_wmb();
@@ -72,33 +76,49 @@ static inline void set_pte_present(struc
 	ptep->pte_low = pte.pte_low;
 }
 
-#define set_pte_atomic(pteptr,pteval) \
-		set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
-#define set_pmd(pmdptr,pmdval) \
-		set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
-#define set_pud(pudptr,pudval) \
-		(*(pudptr) = (pudval))
+static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
+{
+	set_64bit((unsigned long long *)(ptep),native_pte_val(pte));
+}
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+	set_64bit((unsigned long long *)(pmdp),native_pmd_val(pmd));
+}
+static inline void native_set_pud(pud_t *pudp, pud_t pud)
+{
+	*pudp = pud;
+}
 
 /*
  * For PTEs and PDEs, we must clear the P-bit first when clearing a page table
  * entry, so clear the bottom half first and enforce ordering with a compiler
  * barrier.
  */
-static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	ptep->pte_low = 0;
 	smp_wmb();
 	ptep->pte_high = 0;
 }
 
-static inline void pmd_clear(pmd_t *pmd)
+static inline void native_pmd_clear(pmd_t *pmd)
 {
 	u32 *tmp = (u32 *)pmd;
 	*tmp = 0;
 	smp_wmb();
 	*(tmp + 1) = 0;
 }
-#endif
+
+#ifndef CONFIG_PARAVIRT
+#define set_pte(ptep, pte)			native_set_pte(ptep, pte)
+#define set_pte_at(mm, addr, ptep, pte)		native_set_pte_at(mm, addr, ptep, pte)
+#define set_pte_present(mm, addr, ptep, pte)	native_set_pte_present(mm, addr, ptep, pte)
+#define set_pte_atomic(ptep, pte)		native_set_pte_atomic(ptep, pte)
+#define set_pmd(pmdp, pmd)			native_set_pmd(pmdp, pmd)
+#define set_pud(pudp, pud)			native_set_pud(pudp, pud)
+#define pte_clear(mm, addr, ptep)		native_pte_clear(mm, addr, ptep)
+#define pmd_clear(pmd)				native_pmd_clear(pmd)
+#endif
 
 /*
  * Pentium-II erratum A13: in PAE mode we explicitly have to flush
@@ -119,7 +139,7 @@ static inline void pud_clear (pud_t * pu
 #define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
 			pmd_index(address))
 
-static inline pte_t raw_ptep_get_and_clear(pte_t *ptep)
+static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
 {
 	pte_t res;
 
@@ -146,28 +166,21 @@ static inline int pte_none(pte_t pte)
 
 static inline unsigned long pte_pfn(pte_t pte)
 {
-	return (pte.pte_low >> PAGE_SHIFT) |
-		(pte.pte_high << (32 - PAGE_SHIFT));
+	return pte_val(pte) >> PAGE_SHIFT;
 }
 
 extern unsigned long long __supported_pte_mask;
 
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
-	pte_t pte;
-
-	pte.pte_high = (page_nr >> (32 - PAGE_SHIFT)) | \
-					(pgprot_val(pgprot) >> 32);
-	pte.pte_high &= (__supported_pte_mask >> 32);
-	pte.pte_low = ((page_nr << PAGE_SHIFT) | pgprot_val(pgprot)) & \
-							__supported_pte_mask;
-	return pte;
+	return __pte((((unsigned long long)page_nr << PAGE_SHIFT) |
+		      pgprot_val(pgprot)) & __supported_pte_mask);
 }
 
 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 {
-	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) | \
-			pgprot_val(pgprot)) & __supported_pte_mask);
+	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) |
+		      pgprot_val(pgprot)) & __supported_pte_mask);
 }
 
 /*
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -264,6 +264,8 @@ static inline pte_t pte_mkhuge(pte_t pte
 #define pte_update(mm, addr, ptep)		do { } while (0)
 #define pte_update_defer(mm, addr, ptep)	do { } while (0)
 #define paravirt_map_pt_hook(slot, va, pfn)	do { } while (0)
+
+#define raw_ptep_get_and_clear(xp)     native_ptep_get_and_clear(xp)
 #endif
 
 /*

-- 

[patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-pte-accessors.patch --]
[-- Type: text/plain, Size: 19486 bytes --]

Add a set of accessors to pack, unpack and modify page table entries
(at all levels).  This allows a paravirt implementation to control the
contents of pgd/pmd/pte entries.  For example, Xen uses this to
convert the (pseudo-)physical address into a machine address when
populating a pagetable entry, and converting back to pphys address
when an entry is read.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c       |   84 +++++--------------------------------
 arch/i386/kernel/vmi.c            |    6 +-
 include/asm-i386/page.h           |   79 +++++++++++++++++++++++++++++-----
 include/asm-i386/paravirt.h       |   52 +++++++++++++++++-----
 include/asm-i386/pgtable-2level.h |   28 +++++++++---
 include/asm-i386/pgtable-3level.h |   65 +++++++++++++++++-----------
 include/asm-i386/pgtable.h        |    2 
 7 files changed, 186 insertions(+), 130 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -399,78 +399,6 @@ static void native_flush_tlb_single(u32 
 {
 	__native_flush_tlb_single(addr);
 }
-
-#ifndef CONFIG_X86_PAE
-static void native_set_pte(pte_t *ptep, pte_t pteval)
-{
-	*ptep = pteval;
-}
-
-static void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
-{
-	*ptep = pteval;
-}
-
-static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
-	*pmdp = pmdval;
-}
-
-#else /* CONFIG_X86_PAE */
-
-static void native_set_pte(pte_t *ptep, pte_t pte)
-{
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte)
-{
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
-{
-	ptep->pte_low = 0;
-	smp_wmb();
-	ptep->pte_high = pte.pte_high;
-	smp_wmb();
-	ptep->pte_low = pte.pte_low;
-}
-
-static void native_set_pte_atomic(pte_t *ptep, pte_t pteval)
-{
-	set_64bit((unsigned long long *)ptep,pte_val(pteval));
-}
-
-static void native_set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
-	set_64bit((unsigned long long *)pmdp,pmd_val(pmdval));
-}
-
-static void native_set_pud(pud_t *pudp, pud_t pudval)
-{
-	*pudp = pudval;
-}
-
-static void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
-{
-	ptep->pte_low = 0;
-	smp_wmb();
-	ptep->pte_high = 0;
-}
-
-static void native_pmd_clear(pmd_t *pmd)
-{
-	u32 *tmp = (u32 *)pmd;
-	*tmp = 0;
-	smp_wmb();
-	*(tmp + 1) = 0;
-}
-#endif /* CONFIG_X86_PAE */
 
 /* These are in entry.S */
 extern void native_iret(void);
@@ -565,13 +493,25 @@ struct paravirt_ops paravirt_ops = {
 	.set_pmd = native_set_pmd,
 	.pte_update = paravirt_nop,
 	.pte_update_defer = paravirt_nop,
+
+	.ptep_get_and_clear = native_ptep_get_and_clear,
+
 #ifdef CONFIG_X86_PAE
 	.set_pte_atomic = native_set_pte_atomic,
 	.set_pte_present = native_set_pte_present,
 	.set_pud = native_set_pud,
 	.pte_clear = native_pte_clear,
 	.pmd_clear = native_pmd_clear,
+
+	.pmd_val = native_pmd_val,
+	.make_pmd = native_make_pmd,
 #endif
+
+	.pte_val = native_pte_val,
+	.pgd_val = native_pgd_val,
+
+	.make_pte = native_make_pte,
+	.make_pgd = native_make_pgd,
 
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -444,13 +444,13 @@ static void vmi_release_pd(u32 pfn)
         ((level) | (is_current_as(mm, user) ?                           \
                 (VMI_PAGE_DEFER | VMI_PAGE_CURRENT_AS | ((addr) & VMI_PAGE_VA_MASK)) : 0))
 
-static void vmi_update_pte(struct mm_struct *mm, u32 addr, pte_t *ptep)
+static void vmi_update_pte(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.update_pte(ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
 }
 
-static void vmi_update_pte_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
+static void vmi_update_pte_defer(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.update_pte(ptep, vmi_flags_addr_defer(mm, addr, VMI_PAGE_PT, 0));
@@ -463,7 +463,7 @@ static void vmi_set_pte(pte_t *ptep, pte
 	vmi_ops.set_pte(pte, ptep, VMI_PAGE_PT);
 }
 
-static void vmi_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte)
+static void vmi_set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
 {
 	vmi_check_page_type(__pa(ptep) >> PAGE_SHIFT, VMI_PAGE_PTE);
 	vmi_ops.set_pte(pte, ptep, vmi_flags_addr(mm, addr, VMI_PAGE_PT, 0));
===================================================================
--- a/include/asm-i386/page.h
+++ b/include/asm-i386/page.h
@@ -12,7 +12,6 @@
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
 
-
 #ifdef CONFIG_X86_USE_3DNOW
 
 #include <asm/mmx.h>
@@ -42,26 +41,81 @@
  * These are used to make use of C type-checking..
  */
 extern int nx_enabled;
+
 #ifdef CONFIG_X86_PAE
 extern unsigned long long __supported_pte_mask;
 typedef struct { unsigned long pte_low, pte_high; } pte_t;
 typedef struct { unsigned long long pmd; } pmd_t;
 typedef struct { unsigned long long pgd; } pgd_t;
 typedef struct { unsigned long long pgprot; } pgprot_t;
-#define pmd_val(x)	((x).pmd)
-#define pte_val(x)	((x).pte_low | ((unsigned long long)(x).pte_high << 32))
-#define __pmd(x) ((pmd_t) { (x) } )
+
+static inline unsigned long long native_pgd_val(pgd_t pgd)
+{
+	return pgd.pgd;
+}
+
+static inline unsigned long long native_pmd_val(pmd_t pmd)
+{
+	return pmd.pmd;
+}
+
+static inline unsigned long long native_pte_val(pte_t pte)
+{
+	return pte.pte_low | ((unsigned long long)pte.pte_high << 32);
+}
+
+static inline pgd_t native_make_pgd(unsigned long long val)
+{
+	return (pgd_t) { val };
+}
+
+static inline pmd_t native_make_pmd(unsigned long long val)
+{
+	return (pmd_t) { val };
+}
+
+static inline pte_t native_make_pte(unsigned long long val)
+{
+	return (pte_t) { .pte_low = val, .pte_high = (val >> 32) } ;
+}
+
+#ifndef CONFIG_PARAVIRT
+#define pmd_val(x)	native_pmd_val(x)
+#define __pmd(x)	native_make_pmd(x)
+#endif
+
 #define HPAGE_SHIFT	21
 #include <asm-generic/pgtable-nopud.h>
-#else
+#else  /* !CONFIG_X86_PAE */
 typedef struct { unsigned long pte_low; } pte_t;
 typedef struct { unsigned long pgd; } pgd_t;
 typedef struct { unsigned long pgprot; } pgprot_t;
 #define boot_pte_t pte_t /* or would you rather have a typedef */
-#define pte_val(x)	((x).pte_low)
+
+static inline unsigned long native_pgd_val(pgd_t pgd)
+{
+	return pgd.pgd;
+}
+
+static inline unsigned long native_pte_val(pte_t pte)
+{
+	return pte.pte_low;
+}
+
+static inline pgd_t native_make_pgd(unsigned long val)
+{
+	return (pgd_t) { val };
+}
+
+static inline pte_t native_make_pte(unsigned long val)
+{
+	return (pte_t) { .pte_low = val };
+}
+
 #define HPAGE_SHIFT	22
 #include <asm-generic/pgtable-nopmd.h>
-#endif
+#endif	/* CONFIG_X86_PAE */
+
 #define PTE_MASK	PAGE_MASK
 
 #ifdef CONFIG_HUGETLB_PAGE
@@ -71,12 +125,15 @@ typedef struct { unsigned long pgprot; }
 #define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
 #endif
 
-#define pgd_val(x)	((x).pgd)
 #define pgprot_val(x)	((x).pgprot)
-
-#define __pte(x) ((pte_t) { (x) } )
-#define __pgd(x) ((pgd_t) { (x) } )
 #define __pgprot(x)	((pgprot_t) { (x) } )
+
+#ifndef CONFIG_PARAVIRT
+#define pgd_val(x)	native_pgd_val(x)
+#define __pgd(x)	native_make_pgd(x)
+#define pte_val(x)	native_pte_val(x)
+#define __pte(x)	native_make_pte(x)
+#endif
 
 #endif /* !__ASSEMBLY__ */
 
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -2,7 +2,6 @@
 #define __ASM_PARAVIRT_H
 /* Various instructions on x86 need to be replaced for
  * para-virtualization: those hooks are defined here. */
-#include <linux/linkage.h>
 #include <linux/stringify.h>
 #include <asm/page.h>
 
@@ -25,6 +24,8 @@
 #define CLBR_ANY 0x7
 
 #ifndef __ASSEMBLY__
+#include <linux/types.h>
+
 struct thread_struct;
 struct Xgt_desc_struct;
 struct tss_struct;
@@ -53,11 +54,6 @@ struct paravirt_ops
 	unsigned long (*get_wallclock)(void);
 	int (*set_wallclock)(unsigned long);
 	void (*time_init)(void);
-
-	/* All the function pointers here are declared as "fastcall"
-	   so that we get a specific register-based calling
-	   convention.  This makes it easier to implement inline
-	   assembler replacements. */
 
 	void (*cpuid)(unsigned int *eax, unsigned int *ebx,
 		      unsigned int *ecx, unsigned int *edx);
@@ -139,16 +135,33 @@ struct paravirt_ops
 	void (*release_pd)(u32 pfn);
 
 	void (*set_pte)(pte_t *ptep, pte_t pteval);
-	void (*set_pte_at)(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval);
+	void (*set_pte_at)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval);
 	void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
-	void (*pte_update)(struct mm_struct *mm, u32 addr, pte_t *ptep);
-	void (*pte_update_defer)(struct mm_struct *mm, u32 addr, pte_t *ptep);
+	void (*pte_update)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+	void (*pte_update_defer)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+
+ 	pte_t (*ptep_get_and_clear)(pte_t *ptep);
+
 #ifdef CONFIG_X86_PAE
 	void (*set_pte_atomic)(pte_t *ptep, pte_t pteval);
-	void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
+ 	void (*set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte);
 	void (*set_pud)(pud_t *pudp, pud_t pudval);
-	void (*pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
+ 	void (*pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 	void (*pmd_clear)(pmd_t *pmdp);
+
+	unsigned long long (*pte_val)(pte_t);
+	unsigned long long (*pmd_val)(pmd_t);
+	unsigned long long (*pgd_val)(pgd_t);
+
+	pte_t (*make_pte)(unsigned long long pte);
+	pmd_t (*make_pmd)(unsigned long long pmd);
+	pgd_t (*make_pgd)(unsigned long long pgd);
+#else
+	unsigned long (*pte_val)(pte_t);
+	unsigned long (*pgd_val)(pgd_t);
+
+	pte_t (*make_pte)(unsigned long pte);
+	pgd_t (*make_pgd)(unsigned long pgd);
 #endif
 
 	void (*set_lazy_mode)(int mode);
@@ -218,6 +231,8 @@ static inline void __cpuid(unsigned int 
 #define read_cr4() paravirt_ops.read_cr4()
 #define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
 #define write_cr4(x) paravirt_ops.write_cr4(x)
+
+#define raw_ptep_get_and_clear(xp)	(paravirt_ops.ptep_get_and_clear(xp))
 
 static inline void raw_safe_halt(void)
 {
@@ -303,6 +318,17 @@ static inline void halt(void)
 	(paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
 #define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
 
+#define __pte(x)	paravirt_ops.make_pte(x)
+#define __pgd(x)	paravirt_ops.make_pgd(x)
+
+#define pte_val(x)	paravirt_ops.pte_val(x)
+#define pgd_val(x)	paravirt_ops.pgd_val(x)
+
+#ifdef CONFIG_X86_PAE
+#define __pmd(x)	paravirt_ops.make_pmd(x)
+#define pmd_val(x)	paravirt_ops.pmd_val(x)
+#endif
+
 /* The paravirtualized I/O functions */
 static inline void slow_down_io(void) {
 	paravirt_ops.io_delay();
@@ -343,6 +369,7 @@ static inline void setup_secondary_clock
 }
 #endif
 
+
 #ifdef CONFIG_SMP
 static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
 				    unsigned long start_esp)
@@ -370,7 +397,8 @@ static inline void set_pte(pte_t *ptep, 
 	paravirt_ops.set_pte(ptep, pteval);
 }
 
-static inline void set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval)
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval)
 {
 	paravirt_ops.set_pte_at(mm, addr, ptep, pteval);
 }
===================================================================
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -11,11 +11,24 @@
  * within a page table are directly modified.  Thus, the following
  * hook is made available.
  */
+static inline void native_set_pte(pte_t *ptep , pte_t pte)
+{
+	*ptep = pte;
+}
+static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep , pte_t pte)
+{
+	native_set_pte(ptep, pte);
+}
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+	*pmdp = pmd;
+}
 #ifndef CONFIG_PARAVIRT
-#define set_pte(pteptr, pteval) (*(pteptr) = pteval)
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
-#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
-#endif
+#define set_pte(pteptr, pteval)		native_set_pte(pteptr, pteval)
+#define set_pte_at(mm,addr,ptep,pteval) native_set_pte_at(mm, addr, ptep, pteval)
+#define set_pmd(pmdptr, pmdval)		native_set_pmd(pmdptr, pmdval)
+#endif
 
 #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval)
 #define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval)
@@ -23,11 +36,14 @@
 #define pte_clear(mm,addr,xp)	do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
 #define pmd_clear(xp)	do { set_pmd(xp, __pmd(0)); } while (0)
 
-#define raw_ptep_get_and_clear(xp)	__pte(xchg(&(xp)->pte_low, 0))
+static inline pte_t native_ptep_get_and_clear(pte_t *xp)
+{
+	return __pte(xchg(&xp->pte_low, 0));
+}
 
 #define pte_page(x)		pfn_to_page(pte_pfn(x))
 #define pte_none(x)		(!(x).pte_low)
-#define pte_pfn(x)		((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
+#define pte_pfn(x)		(pte_val(x) >> PAGE_SHIFT)
 #define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 #define pfn_pmd(pfn, prot)	__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 
===================================================================
--- a/include/asm-i386/pgtable-3level.h
+++ b/include/asm-i386/pgtable-3level.h
@@ -42,20 +42,23 @@ static inline int pte_exec_kernel(pte_t 
 	return pte_x(pte);
 }
 
-#ifndef CONFIG_PARAVIRT
 /* Rules for using set_pte: the pte being assigned *must* be
  * either not present or in a state where the hardware will
  * not attempt to update the pte.  In places where this is
  * not possible, use pte_get_and_clear to obtain the old pte
  * value and then use set_pte to update it.  -ben
  */
-static inline void set_pte(pte_t *ptep, pte_t pte)
+static inline void native_set_pte(pte_t *ptep, pte_t pte)
 {
 	ptep->pte_high = pte.pte_high;
 	smp_wmb();
 	ptep->pte_low = pte.pte_low;
 }
-#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
+static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
+				     pte_t *ptep , pte_t pte)
+{
+	native_set_pte(ptep, pte);
+}
 
 /*
  * Since this is only called on user PTEs, and the page fault handler
@@ -63,7 +66,8 @@ static inline void set_pte(pte_t *ptep, 
  * we are justified in merely clearing the PTE present bit, followed
  * by a set.  The ordering here is important.
  */
-static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+static inline void native_set_pte_present(struct mm_struct *mm, unsigned long addr,
+					  pte_t *ptep, pte_t pte)
 {
 	ptep->pte_low = 0;
 	smp_wmb();
@@ -72,33 +76,49 @@ static inline void set_pte_present(struc
 	ptep->pte_low = pte.pte_low;
 }
 
-#define set_pte_atomic(pteptr,pteval) \
-		set_64bit((unsigned long long *)(pteptr),pte_val(pteval))
-#define set_pmd(pmdptr,pmdval) \
-		set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval))
-#define set_pud(pudptr,pudval) \
-		(*(pudptr) = (pudval))
+static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
+{
+	set_64bit((unsigned long long *)(ptep),native_pte_val(pte));
+}
+static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+	set_64bit((unsigned long long *)(pmdp),native_pmd_val(pmd));
+}
+static inline void native_set_pud(pud_t *pudp, pud_t pud)
+{
+	*pudp = pud;
+}
 
 /*
  * For PTEs and PDEs, we must clear the P-bit first when clearing a page table
  * entry, so clear the bottom half first and enforce ordering with a compiler
  * barrier.
  */
-static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+static inline void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	ptep->pte_low = 0;
 	smp_wmb();
 	ptep->pte_high = 0;
 }
 
-static inline void pmd_clear(pmd_t *pmd)
+static inline void native_pmd_clear(pmd_t *pmd)
 {
 	u32 *tmp = (u32 *)pmd;
 	*tmp = 0;
 	smp_wmb();
 	*(tmp + 1) = 0;
 }
-#endif
+
+#ifndef CONFIG_PARAVIRT
+#define set_pte(ptep, pte)			native_set_pte(ptep, pte)
+#define set_pte_at(mm, addr, ptep, pte)		native_set_pte_at(mm, addr, ptep, pte)
+#define set_pte_present(mm, addr, ptep, pte)	native_set_pte_present(mm, addr, ptep, pte)
+#define set_pte_atomic(ptep, pte)		native_set_pte_atomic(ptep, pte)
+#define set_pmd(pmdp, pmd)			native_set_pmd(pmdp, pmd)
+#define set_pud(pudp, pud)			native_set_pud(pudp, pud)
+#define pte_clear(mm, addr, ptep)		native_pte_clear(mm, addr, ptep)
+#define pmd_clear(pmd)				native_pmd_clear(pmd)
+#endif
 
 /*
  * Pentium-II erratum A13: in PAE mode we explicitly have to flush
@@ -119,7 +139,7 @@ static inline void pud_clear (pud_t * pu
 #define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \
 			pmd_index(address))
 
-static inline pte_t raw_ptep_get_and_clear(pte_t *ptep)
+static inline pte_t native_ptep_get_and_clear(pte_t *ptep)
 {
 	pte_t res;
 
@@ -146,28 +166,21 @@ static inline int pte_none(pte_t pte)
 
 static inline unsigned long pte_pfn(pte_t pte)
 {
-	return (pte.pte_low >> PAGE_SHIFT) |
-		(pte.pte_high << (32 - PAGE_SHIFT));
+	return pte_val(pte) >> PAGE_SHIFT;
 }
 
 extern unsigned long long __supported_pte_mask;
 
 static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
 {
-	pte_t pte;
-
-	pte.pte_high = (page_nr >> (32 - PAGE_SHIFT)) | \
-					(pgprot_val(pgprot) >> 32);
-	pte.pte_high &= (__supported_pte_mask >> 32);
-	pte.pte_low = ((page_nr << PAGE_SHIFT) | pgprot_val(pgprot)) & \
-							__supported_pte_mask;
-	return pte;
+	return __pte((((unsigned long long)page_nr << PAGE_SHIFT) |
+		      pgprot_val(pgprot)) & __supported_pte_mask);
 }
 
 static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 {
-	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) | \
-			pgprot_val(pgprot)) & __supported_pte_mask);
+	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) |
+		      pgprot_val(pgprot)) & __supported_pte_mask);
 }
 
 /*
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -264,6 +264,8 @@ static inline pte_t pte_mkhuge(pte_t pte
 #define pte_update(mm, addr, ptep)		do { } while (0)
 #define pte_update_defer(mm, addr, ptep)	do { } while (0)
 #define paravirt_map_pt_hook(slot, va, pfn)	do { } while (0)
+
+#define raw_ptep_get_and_clear(xp)     native_ptep_get_and_clear(xp)
 #endif
 
 /*

-- 

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Andi Kleen]

On Monday 02 April 2007 07:56, Jeremy Fitzhardinge wrote:
> Add a set of accessors to pack, unpack and modify page table entries
> (at all levels).  This allows a paravirt implementation to control the
> contents of pgd/pmd/pte entries.  For example, Xen uses this to
> convert the (pseudo-)physical address into a machine address when
> populating a pagetable entry, and converting back to pphys address
> when an entry is read.

What do the benchmarks say with CONFIG_PARAVIRT on native hardware
compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 

-Andi

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Rusty Russell]

On Mon, 2007-04-02 at 08:12 +0200, Andi Kleen wrote:
> On Monday 02 April 2007 07:56, Jeremy Fitzhardinge wrote:
> > Add a set of accessors to pack, unpack and modify page table entries
> > (at all levels).  This allows a paravirt implementation to control the
> > contents of pgd/pmd/pte entries.  For example, Xen uses this to
> > convert the (pseudo-)physical address into a machine address when
> > populating a pagetable entry, and converting back to pphys address
> > when an entry is read.
> 
> What do the benchmarks say with CONFIG_PARAVIRT on native hardware
> compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 

This patch by itself, definitely: I gathered stats previously simply
measuring the number of calls, and it's comparable to the other calls we
had to patch.

So it's clear that the patch infrastructure needs to cover them.  We can
debate whether we should extend patching to everything as 1/17 does, or
just to mkpte and pteval.

I'd still like to see new microbench stats tho.

Cheers!
Rusty.

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> What do the benchmarks say with CONFIG_PARAVIRT on native hardware
> compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 
>   

I haven't measured it, but I'll do some experiments.

    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> What do the benchmarks say with CONFIG_PARAVIRT on native hardware
> compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 
>   

I haven't measured it, but I'll do some experiments.

    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> What do the benchmarks say with CONFIG_PARAVIRT on native hardware
> compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 

Barely.  There's a slight hit for not using patching, and patching is
almost identical to native performance.  The most noticeable difference
is in the null syscall microbenchmark, but once you get to complex
things the difference is in the noise.

Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host                 OS  Mhz null null      open slct sig  sig  fork exec sh  
                             call  I/O stat clos TCP  inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
non-paravirt
ezr       Linux 2.6.21- 1000 0.25 0.52 31.6 34.7 10.3 1.03 5.31 726. 1565 4520
ezr       Linux 2.6.21- 1000 0.25 0.52 31.8 34.7 12.6 1.03 5.41 725. 1564 4585
ezr       Linux 2.6.21- 1000 0.25 0.55 31.7 34.5 11.8 1.02 5.47 720. 1595 4518

paravirt, no patching
ezr       Linux 2.6.21- 1000 0.28 0.55 31.3 34.3 10.0 1.05 5.56 747. 1621 4675
ezr       Linux 2.6.21- 1000 0.28 0.56 31.5 34.3 12.9 1.05 5.66 755. 1629 4684
ezr       Linux 2.6.21- 1000 0.28 0.55 31.8 34.5 12.5 1.05 5.45 747. 1622 4695

paravirt, patching
ezr       Linux 2.6.21- 1000 0.25 0.53 31.8 34.4 10.1 1.04 5.44 730. 1583 4600
ezr       Linux 2.6.21- 1000 0.26 0.55 32.1 35.2 13.3 1.03 5.48 748. 1589 4606
ezr       Linux 2.6.21- 1000 0.26 0.54 32.0 34.9 14.1 1.04 5.43 752. 1606 4647


    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Ingo Molnar]

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> > What do the benchmarks say with CONFIG_PARAVIRT on native hardware 
> > compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer?
> 
> Barely.  There's a slight hit for not using patching, and patching is 
> almost identical to native performance.  The most noticeable 
> difference is in the null syscall microbenchmark, but once you get to 
> complex things the difference is in the noise.

i'd not call this 'barely' or 'noise'! Look:

> Processor, Processes - times in microseconds - smaller is better
> ------------------------------------------------------------------------------
> Host                 OS  Mhz null null      open slct sig  sig  fork exec sh  
>                              call  I/O stat clos TCP  inst hndl proc proc proc
> --------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
> non-paravirt
> ezr       Linux 2.6.21- 1000 0.25 0.52 31.6 34.7 10.3 1.03 5.31 726. 1565 4520
> ezr       Linux 2.6.21- 1000 0.25 0.52 31.8 34.7 12.6 1.03 5.41 725. 1564 4585
> ezr       Linux 2.6.21- 1000 0.25 0.55 31.7 34.5 11.8 1.02 5.47 720. 1595 4518
> 
> paravirt, no patching
> ezr       Linux 2.6.21- 1000 0.28 0.55 31.3 34.3 10.0 1.05 5.56 747. 1621 4675
> ezr       Linux 2.6.21- 1000 0.28 0.56 31.5 34.3 12.9 1.05 5.66 755. 1629 4684
> ezr       Linux 2.6.21- 1000 0.28 0.55 31.8 34.5 12.5 1.05 5.45 747. 1622 4695

the main metric we are interested in is the overhead for people who just 
want to run the non-patched native kernel that has CONFIG_PARAVIRT 
enabled (99%+ of the users at the moment), so the delta is:

 null:              +12.0%
 null IO:            +7.5%
 stat:        within noise
 open/close:  within noise
 TCP:                ~5.0%
 signal install:      2.0%
 signal handle:       4.7%
 fork:                2.7%
 exec:                3.6%
 shell:               3.6%

this is not 'barely measurable' but 'BLOODY LARGE' overhead. Really. I 
mean for something as complex as exec we still are 'a couple of percent' 
slower? Linux has literally _dozens_ of important but inactive features 
in every critical fastpath and in every critical system call, and if 
each took 'just a few percent', we'd be a few _times_ slower as an end 
result, for features that are not even used! The answer to any such 
overhead is: "get your act together and stop burdening those who dont 
want to use that feature" ... This is a basic engineering requirement.

> paravirt, patching
> ezr       Linux 2.6.21- 1000 0.25 0.53 31.8 34.4 10.1 1.04 5.44 730. 1583 4600
> ezr       Linux 2.6.21- 1000 0.26 0.55 32.1 35.2 13.3 1.03 5.48 748. 1589 4606
> ezr       Linux 2.6.21- 1000 0.26 0.54 32.0 34.9 14.1 1.04 5.43 752. 1606 4647

i guess this pretty much makes the case for patching ...

	Ingo

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Andi Kleen]

> > paravirt, patching
> > ezr       Linux 2.6.21- 1000 0.25 0.53 31.8 34.4 10.1 1.04 5.44 730. 1583 4600
> > ezr       Linux 2.6.21- 1000 0.26 0.55 32.1 35.2 13.3 1.03 5.48 748. 1589 4606
> > ezr       Linux 2.6.21- 1000 0.26 0.54 32.0 34.9 14.1 1.04 5.43 752. 1606 4647
> 
> i guess this pretty much makes the case for patching ...

Yes, we definitely want to patch. Still it's unclear why it still shows slower stat.
Or could that be benchmark noise?

-Andi

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Ingo Molnar wrote:
> the main metric we are interested in is the overhead for people who just 
> want to run the non-patched native kernel that has CONFIG_PARAVIRT 
> enabled (99%+ of the users at the moment), so the delta is:
>
>  null:              +12.0%
>  null IO:            +7.5%
>  stat:        within noise
>  open/close:  within noise
>  TCP:                ~5.0%
>  signal install:      2.0%
>  signal handle:       4.7%
>  fork:                2.7%
>  exec:                3.6%
>  shell:               3.6%
>   
Hm, I don't think you can get this much precision out of these numbers. 
I noticed larger variations from boot-to-boot running the same test.

> this is not 'barely measurable' but 'BLOODY LARGE' overhead.

Yes.  Fortunately there's a noticable difference between native and
unpatched paravirt, because it shows all the effort we put into patching
is worthwhile.

>> paravirt, patching
>> ezr       Linux 2.6.21- 1000 0.25 0.53 31.8 34.4 10.1 1.04 5.44 730. 1583 4600
>> ezr       Linux 2.6.21- 1000 0.26 0.55 32.1 35.2 13.3 1.03 5.48 748. 1589 4606
>> ezr       Linux 2.6.21- 1000 0.26 0.54 32.0 34.9 14.1 1.04 5.43 752. 1606 4647
>>     
>
> i guess this pretty much makes the case for patching ...
>   

Right, that's why there's patching.


    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Ingo Molnar]

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Ingo Molnar wrote:
> > the main metric we are interested in is the overhead for people who just 
> > want to run the non-patched native kernel that has CONFIG_PARAVIRT 
> > enabled (99%+ of the users at the moment), so the delta is:
> >
> >  null:              +12.0%
> >  null IO:            +7.5%
> >  stat:        within noise
> >  open/close:  within noise
> >  TCP:                ~5.0%
> >  signal install:      2.0%
> >  signal handle:       4.7%
> >  fork:                2.7%
> >  exec:                3.6%
> >  shell:               3.6%
> >   
>
> Hm, I don't think you can get this much precision out of these 
> numbers. I noticed larger variations from boot-to-boot running the 
> same test.

sure. i simply took the middle numbers. But there's definitely a 'few 
percents' trend in the numbers.

> > this is not 'barely measurable' but 'BLOODY LARGE' overhead.
> 
> Yes.  Fortunately there's a noticable difference between native and 
> unpatched paravirt, because it shows all the effort we put into 
> patching is worthwhile.

if only it were not such an ugly piece of code? ;)

	Ingo

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Ingo Molnar wrote:
> sure. i simply took the middle numbers. But there's definitely a 'few 
> percents' trend in the numbers.
>   

Yep. I guess the thing that coloured my summary is that I found overhead
of unpatched paravirt_ops calls surprisingly small.  I was really
expecting more like ~10% hit, but only null syscall approached that.

>>> this is not 'barely measurable' but 'BLOODY LARGE' overhead.
>>>       
>> Yes.  Fortunately there's a noticable difference between native and 
>> unpatched paravirt, because it shows all the effort we put into 
>> patching is worthwhile.
>>     
>
> if only it were not such an ugly piece of code? ;)
>   

Sigh, yes.  I've cleaned it up a bit since the last post, and commented
it, but I couldn't do much with its essential ugliness.  But I guess it
just got promoted from "ugly" to "ugly but necessary".

    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Andi Kleen]

On Wednesday 04 April 2007 11:25:57 Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> > What do the benchmarks say with CONFIG_PARAVIRT on native hardware
> > compared to !CONFIG_PARAVIRT. e.g. does lmbench suffer? 
> 
> Barely.  There's a slight hit for not using patching, and patching is
> almost identical to native performance.  The most noticeable difference
> is in the null syscall microbenchmark, but once you get to complex
> things the difference is in the noise.

Why is there a difference for null syscall? I had assumed we patched all the 
fast path cases relevant there. Do you have an idea where it comes from?

-Andi

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> Why is there a difference for null syscall? I had assumed we patched all the 
> fast path cases relevant there. Do you have an idea where it comes from?

Sure.  There's indirect calls for things like sti/cli/iret.  It goes
back to native speed when you patch the real instructions inline.

    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Andi Kleen]

On Wednesday 04 April 2007 17:45:44 Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> > Why is there a difference for null syscall? I had assumed we patched all the 
> > fast path cases relevant there. Do you have an idea where it comes from?
> 
> Sure.  There's indirect calls for things like sti/cli/iret.  It goes
> back to native speed when you patch the real instructions inline.

I was talking about the patched case. It seemed to be a little slower
too, but in theory it shouldn't have been, no? 

-Andi

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> I was talking about the patched case. It seemed to be a little slower
> too, but in theory it shouldn't have been, no? 

Oh, the .25 vs .26?  That's definitely noise; on other runs I see no
difference:

paravirt, patched, busy machine
ezr       Linux 2.6.21- 1000 0.25 0.52 31.3 34.4 12.7 1.02 5.44 743. 1578 4582
ezr       Linux 2.6.21- 1000 0.25 0.53 31.4 34.2 12.1 1.02 5.27 736. 1594 4806
ezr       Linux 2.6.21- 1000 0.25 0.52 31.5 34.4 14.3 1.02 5.49 736. 1587 4601

(I didn't use this result because I did it on a fairly busy machine, but
the best-case numbers are actually somewhat better than the run on a
completely quiet machine.)


    J

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Rusty Russell]

On Wed, 2007-04-04 at 17:56 +0200, Andi Kleen wrote:
> On Wednesday 04 April 2007 17:45:44 Jeremy Fitzhardinge wrote:
> > Andi Kleen wrote:
> > > Why is there a difference for null syscall? I had assumed we patched all the 
> > > fast path cases relevant there. Do you have an idea where it comes from?
> > 
> > Sure.  There's indirect calls for things like sti/cli/iret.  It goes
> > back to native speed when you patch the real instructions inline.
> 
> I was talking about the patched case. It seemed to be a little slower
> too, but in theory it shouldn't have been, no? 

You'll still have the damage inflicted on gcc's optimizer, though.

Rusty.

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Rusty Russell]

On Wed, 2007-04-04 at 17:56 +0200, Andi Kleen wrote:
> On Wednesday 04 April 2007 17:45:44 Jeremy Fitzhardinge wrote:
> > Andi Kleen wrote:
> > > Why is there a difference for null syscall? I had assumed we patched all the 
> > > fast path cases relevant there. Do you have an idea where it comes from?
> > 
> > Sure.  There's indirect calls for things like sti/cli/iret.  It goes
> > back to native speed when you patch the real instructions inline.
> 
> I was talking about the patched case. It seemed to be a little slower
> too, but in theory it shouldn't have been, no? 

You'll still have the damage inflicted on gcc's optimizer, though.

Rusty.

Re: [patch 04/17] Add pagetable accessors to pack and unpack pagetable entries

[Jeremy Fitzhardinge]

Rusty Russell wrote:
> You'll still have the damage inflicted on gcc's optimizer, though.

Well, I could remove the clobbers for PVOP_CALL[0-2] and add the
appropriate push/pops, and put similar push/pop wrappers around all the
called functions.  But it doesn't make it any prettier.

    J

[patch 05/17] Hooks to set up initial pagetable

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-memory-init.patch --]
[-- Type: text/plain, Size: 11632 bytes --]

This patch introduces paravirt_ops hooks to control how the kernel's
initial pagetable is set up.

In the case of a native boot, the very early bootstrap code creates a
simple non-PAE pagetable to map the kernel and physical memory.  When
the VM subsystem is initialized, it creates a proper pagetable which
respects the PAE mode, large pages, etc.

When booting under a hypervisor, there are many possibilities for what
paging environment the hypervisor establishes for the guest kernel, so
the constructon of the kernel's pagetable depends on the hypervisor.

In the case of Xen, the hypervisor boots the kernel with a fully
constructed pagetable, which is already using PAE if necessary.  Also,
Xen requires particular care when constructing pagetables to make sure
all pagetables are always mapped read-only.

In order to make this easier, kernel's initial pagetable construction
has been changed to only allocate and initialize a pagetable page if
there's no page already present in the pagetable.  This allows the Xen
paravirt backend to make a copy of the hypervisor-provided pagetable,
allowing the kernel to establish any more mappings it needs while
keeping the existing ones.

A slightly subtle point which is worth highlighting here is that Xen
requires all kernel mappings to share the same pte_t pages between all
pagetables, so that updating a kernel page's mapping in one pagetable
is reflected in all other pagetables.  This makes it possible to
allocate a page and attach it to a pagetable without having to
explicitly enumerate that page's mapping in all pagetables.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c |    3 
 arch/i386/mm/init.c         |  158 +++++++++++++++++++++++++++++--------------
 include/asm-i386/paravirt.h |   17 ++++
 include/asm-i386/pgtable.h  |   16 ++++
 4 files changed, 142 insertions(+), 52 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -476,6 +476,9 @@ struct paravirt_ops paravirt_ops = {
 #endif
 	.set_lazy_mode = paravirt_nop,
 
+	.pagetable_setup_start = native_pagetable_setup_start,
+	.pagetable_setup_done = native_pagetable_setup_done,
+
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
===================================================================
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -42,6 +42,7 @@
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
+#include <asm/paravirt.h>
 
 unsigned int __VMALLOC_RESERVE = 128 << 20;
 
@@ -62,6 +63,7 @@ static pmd_t * __init one_md_table_init(
 		
 #ifdef CONFIG_X86_PAE
 	pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+
 	paravirt_alloc_pd(__pa(pmd_table) >> PAGE_SHIFT);
 	set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
 	pud = pud_offset(pgd, 0);
@@ -83,12 +85,10 @@ static pte_t * __init one_page_table_ini
 {
 	if (pmd_none(*pmd)) {
 		pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+
 		paravirt_alloc_pt(__pa(page_table) >> PAGE_SHIFT);
 		set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
-		if (page_table != pte_offset_kernel(pmd, 0))
-			BUG();	
-
-		return page_table;
+		BUG_ON(page_table != pte_offset_kernel(pmd, 0));
 	}
 	
 	return pte_offset_kernel(pmd, 0);
@@ -119,7 +119,7 @@ static void __init page_table_range_init
 	pgd = pgd_base + pgd_idx;
 
 	for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
-		if (pgd_none(*pgd)) 
+		if (!(pgd_val(*pgd) & _PAGE_PRESENT))
 			one_md_table_init(pgd);
 		pud = pud_offset(pgd, vaddr);
 		pmd = pmd_offset(pud, vaddr);
@@ -158,7 +158,11 @@ static void __init kernel_physical_mappi
 	pfn = 0;
 
 	for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
-		pmd = one_md_table_init(pgd);
+		if (!(pgd_val(*pgd) & _PAGE_PRESENT))
+			pmd = one_md_table_init(pgd);
+		else
+			pmd = pmd_offset(pud_offset(pgd, PAGE_OFFSET), PAGE_OFFSET);
+
 		if (pfn >= max_low_pfn)
 			continue;
 		for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) {
@@ -167,20 +171,26 @@ static void __init kernel_physical_mappi
 			/* Map with big pages if possible, otherwise create normal page tables. */
 			if (cpu_has_pse) {
 				unsigned int address2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1;
-
-				if (is_kernel_text(address) || is_kernel_text(address2))
-					set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
-				else
-					set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+				if (!pmd_present(*pmd)) {
+					if (is_kernel_text(address) || is_kernel_text(address2))
+						set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
+					else
+						set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+				}
 				pfn += PTRS_PER_PTE;
 			} else {
 				pte = one_page_table_init(pmd);
 
-				for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; pte++, pfn++, pte_ofs++) {
-						if (is_kernel_text(address))
-							set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
-						else
-							set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
+				for (pte_ofs = 0;
+				     pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn;
+				     pte++, pfn++, pte_ofs++, address += PAGE_SIZE) {
+					if (pte_present(*pte))
+						continue;
+
+					if (is_kernel_text(address))
+						set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
+					else
+						set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
 				}
 			}
 		}
@@ -337,44 +347,36 @@ extern void __init remap_numa_kva(void);
 #define remap_numa_kva() do {} while (0)
 #endif
 
-static void __init pagetable_init (void)
-{
-	unsigned long vaddr;
-	pgd_t *pgd_base = swapper_pg_dir;
-
+void __init native_pagetable_setup_start(pgd_t *base)
+{
 #ifdef CONFIG_X86_PAE
 	int i;
-	/* Init entries of the first-level page table to the zero page */
-	for (i = 0; i < PTRS_PER_PGD; i++)
-		set_pgd(pgd_base + i, __pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
+
+	/*
+	 * Init entries of the first-level page table to the
+	 * zero page, if they haven't already been set up.
+	 *
+	 * In a normal native boot, we'll be running on a
+	 * pagetable rooted in swapper_pg_dir, but not in PAE
+	 * mode, so this will end up clobbering the mappings
+	 * for the lower 24Mbytes of the address space,
+	 * without affecting the kernel address space.
+	 */
+	for (i = 0; i < USER_PTRS_PER_PGD; i++)
+		set_pgd(&base[i],
+			__pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
+
+	/* Make sure kernel address space is empty so that a pagetable
+	   will be allocated for it. */
+	memset(&base[USER_PTRS_PER_PGD], 0,
+	       KERNEL_PGD_PTRS * sizeof(pgd_t));
 #else
 	paravirt_alloc_pd(__pa(swapper_pg_dir) >> PAGE_SHIFT);
 #endif
-
-	/* Enable PSE if available */
-	if (cpu_has_pse) {
-		set_in_cr4(X86_CR4_PSE);
-	}
-
-	/* Enable PGE if available */
-	if (cpu_has_pge) {
-		set_in_cr4(X86_CR4_PGE);
-		__PAGE_KERNEL |= _PAGE_GLOBAL;
-		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
-	}
-
-	kernel_physical_mapping_init(pgd_base);
-	remap_numa_kva();
-
-	/*
-	 * Fixed mappings, only the page table structure has to be
-	 * created - mappings will be set by set_fixmap():
-	 */
-	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-	page_table_range_init(vaddr, 0, pgd_base);
-
-	permanent_kmaps_init(pgd_base);
-
+}
+
+void __init native_pagetable_setup_done(pgd_t *base)
+{
 #ifdef CONFIG_X86_PAE
 	/*
 	 * Add low memory identity-mappings - SMP needs it when
@@ -383,8 +385,62 @@ static void __init pagetable_init (void)
 	 * All user-space mappings are explicitly cleared after
 	 * SMP startup.
 	 */
-	set_pgd(&pgd_base[0], pgd_base[USER_PTRS_PER_PGD]);
-#endif
+	set_pgd(&base[0], base[USER_PTRS_PER_PGD]);
+#endif
+}
+
+/*
+ * Build a proper pagetable for the kernel mappings.  Up until this
+ * point, we've been running on some set of pagetables constructed by
+ * the boot process.
+ *
+ * If we're booting on native hardware, this will be a pagetable
+ * constructed in arch/i386/kernel/head.S, and not running in PAE mode
+ * (even if we'll end up running in PAE).  The root of the pagetable
+ * will be swapper_pg_dir.
+ *
+ * If we're booting paravirtualized under a hypervisor, then there are
+ * more options: we may already be running PAE, and the pagetable may
+ * or may not be based in swapper_pg_dir.  In any case,
+ * paravirt_pagetable_setup_start() will set up swapper_pg_dir
+ * appropriately for the rest of the initialization to work.
+ *
+ * In general, pagetable_init() assumes that the pagetable may already
+ * be partially populated, and so it avoids stomping on any existing
+ * mappings.
+ */
+static void __init pagetable_init (void)
+{
+	unsigned long vaddr, end;
+	pgd_t *pgd_base = swapper_pg_dir;
+
+	paravirt_pagetable_setup_start(pgd_base);
+
+	/* Enable PSE if available */
+	if (cpu_has_pse)
+		set_in_cr4(X86_CR4_PSE);
+
+	/* Enable PGE if available */
+	if (cpu_has_pge) {
+		set_in_cr4(X86_CR4_PGE);
+		__PAGE_KERNEL |= _PAGE_GLOBAL;
+		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
+	}
+
+	kernel_physical_mapping_init(pgd_base);
+	remap_numa_kva();
+
+	/*
+	 * Fixed mappings, only the page table structure has to be
+	 * created - mappings will be set by set_fixmap():
+	 */
+	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
+	page_table_range_init(vaddr, end, pgd_base);
+
+	permanent_kmaps_init(pgd_base);
+
+	paravirt_pagetable_setup_done(pgd_base);
 }
 
 #if defined(CONFIG_SOFTWARE_SUSPEND) || defined(CONFIG_ACPI_SLEEP)
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -2,10 +2,11 @@
 #define __ASM_PARAVIRT_H
 /* Various instructions on x86 need to be replaced for
  * para-virtualization: those hooks are defined here. */
+
+#ifdef CONFIG_PARAVIRT
 #include <linux/stringify.h>
 #include <asm/page.h>
 
-#ifdef CONFIG_PARAVIRT
 /* These are the most performance critical ops, so we want to be able to patch
  * callers */
 #define PARAVIRT_IRQ_DISABLE 0
@@ -48,6 +49,9 @@ struct paravirt_ops
 	void (*arch_setup)(void);
 	char *(*memory_setup)(void);
 	void (*init_IRQ)(void);
+
+	void (*pagetable_setup_start)(pgd_t *pgd_base);
+	void (*pagetable_setup_done)(pgd_t *pgd_base);
 
 	void (*banner)(void);
 
@@ -369,6 +373,17 @@ static inline void setup_secondary_clock
 }
 #endif
 
+static inline void paravirt_pagetable_setup_start(pgd_t *base)
+{
+	if (paravirt_ops.pagetable_setup_start)
+		(*paravirt_ops.pagetable_setup_start)(base);
+}
+
+static inline void paravirt_pagetable_setup_done(pgd_t *base)
+{
+	if (paravirt_ops.pagetable_setup_done)
+		(*paravirt_ops.pagetable_setup_done)(base);
+}
 
 #ifdef CONFIG_SMP
 static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -512,6 +512,22 @@ do {									\
  * tables contain all the necessary information.
  */
 #define update_mmu_cache(vma,address,pte) do { } while (0)
+
+void native_pagetable_setup_start(pgd_t *base);
+void native_pagetable_setup_done(pgd_t *base);
+
+#ifndef CONFIG_PARAVIRT
+static inline void paravirt_pagetable_setup_start(pgd_t *base)
+{
+	native_pagetable_setup_start(base);
+}
+
+static inline void paravirt_pagetable_setup_done(pgd_t *base)
+{
+	native_pagetable_setup_done(base);
+}
+#endif	/* !CONFIG_PARAVIRT */
+
 #endif /* !__ASSEMBLY__ */
 
 #ifdef CONFIG_FLATMEM

-- 

[patch 05/17] Hooks to set up initial pagetable

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-memory-init.patch --]
[-- Type: text/plain, Size: 11984 bytes --]

This patch introduces paravirt_ops hooks to control how the kernel's
initial pagetable is set up.

In the case of a native boot, the very early bootstrap code creates a
simple non-PAE pagetable to map the kernel and physical memory.  When
the VM subsystem is initialized, it creates a proper pagetable which
respects the PAE mode, large pages, etc.

When booting under a hypervisor, there are many possibilities for what
paging environment the hypervisor establishes for the guest kernel, so
the constructon of the kernel's pagetable depends on the hypervisor.

In the case of Xen, the hypervisor boots the kernel with a fully
constructed pagetable, which is already using PAE if necessary.  Also,
Xen requires particular care when constructing pagetables to make sure
all pagetables are always mapped read-only.

In order to make this easier, kernel's initial pagetable construction
has been changed to only allocate and initialize a pagetable page if
there's no page already present in the pagetable.  This allows the Xen
paravirt backend to make a copy of the hypervisor-provided pagetable,
allowing the kernel to establish any more mappings it needs while
keeping the existing ones.

A slightly subtle point which is worth highlighting here is that Xen
requires all kernel mappings to share the same pte_t pages between all
pagetables, so that updating a kernel page's mapping in one pagetable
is reflected in all other pagetables.  This makes it possible to
allocate a page and attach it to a pagetable without having to
explicitly enumerate that page's mapping in all pagetables.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: William Irwin <bill.irwin@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c |    3 
 arch/i386/mm/init.c         |  158 +++++++++++++++++++++++++++++--------------
 include/asm-i386/paravirt.h |   17 ++++
 include/asm-i386/pgtable.h  |   16 ++++
 4 files changed, 142 insertions(+), 52 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -476,6 +476,9 @@ struct paravirt_ops paravirt_ops = {
 #endif
 	.set_lazy_mode = paravirt_nop,
 
+	.pagetable_setup_start = native_pagetable_setup_start,
+	.pagetable_setup_done = native_pagetable_setup_done,
+
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
===================================================================
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -42,6 +42,7 @@
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>
+#include <asm/paravirt.h>
 
 unsigned int __VMALLOC_RESERVE = 128 << 20;
 
@@ -62,6 +63,7 @@ static pmd_t * __init one_md_table_init(
 		
 #ifdef CONFIG_X86_PAE
 	pmd_table = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+
 	paravirt_alloc_pd(__pa(pmd_table) >> PAGE_SHIFT);
 	set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT));
 	pud = pud_offset(pgd, 0);
@@ -83,12 +85,10 @@ static pte_t * __init one_page_table_ini
 {
 	if (pmd_none(*pmd)) {
 		pte_t *page_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+
 		paravirt_alloc_pt(__pa(page_table) >> PAGE_SHIFT);
 		set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE));
-		if (page_table != pte_offset_kernel(pmd, 0))
-			BUG();	
-
-		return page_table;
+		BUG_ON(page_table != pte_offset_kernel(pmd, 0));
 	}
 	
 	return pte_offset_kernel(pmd, 0);
@@ -119,7 +119,7 @@ static void __init page_table_range_init
 	pgd = pgd_base + pgd_idx;
 
 	for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) {
-		if (pgd_none(*pgd)) 
+		if (!(pgd_val(*pgd) & _PAGE_PRESENT))
 			one_md_table_init(pgd);
 		pud = pud_offset(pgd, vaddr);
 		pmd = pmd_offset(pud, vaddr);
@@ -158,7 +158,11 @@ static void __init kernel_physical_mappi
 	pfn = 0;
 
 	for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) {
-		pmd = one_md_table_init(pgd);
+		if (!(pgd_val(*pgd) & _PAGE_PRESENT))
+			pmd = one_md_table_init(pgd);
+		else
+			pmd = pmd_offset(pud_offset(pgd, PAGE_OFFSET), PAGE_OFFSET);
+
 		if (pfn >= max_low_pfn)
 			continue;
 		for (pmd_idx = 0; pmd_idx < PTRS_PER_PMD && pfn < max_low_pfn; pmd++, pmd_idx++) {
@@ -167,20 +171,26 @@ static void __init kernel_physical_mappi
 			/* Map with big pages if possible, otherwise create normal page tables. */
 			if (cpu_has_pse) {
 				unsigned int address2 = (pfn + PTRS_PER_PTE - 1) * PAGE_SIZE + PAGE_OFFSET + PAGE_SIZE-1;
-
-				if (is_kernel_text(address) || is_kernel_text(address2))
-					set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
-				else
-					set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+				if (!pmd_present(*pmd)) {
+					if (is_kernel_text(address) || is_kernel_text(address2))
+						set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE_EXEC));
+					else
+						set_pmd(pmd, pfn_pmd(pfn, PAGE_KERNEL_LARGE));
+				}
 				pfn += PTRS_PER_PTE;
 			} else {
 				pte = one_page_table_init(pmd);
 
-				for (pte_ofs = 0; pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn; pte++, pfn++, pte_ofs++) {
-						if (is_kernel_text(address))
-							set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
-						else
-							set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
+				for (pte_ofs = 0;
+				     pte_ofs < PTRS_PER_PTE && pfn < max_low_pfn;
+				     pte++, pfn++, pte_ofs++, address += PAGE_SIZE) {
+					if (pte_present(*pte))
+						continue;
+
+					if (is_kernel_text(address))
+						set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC));
+					else
+						set_pte(pte, pfn_pte(pfn, PAGE_KERNEL));
 				}
 			}
 		}
@@ -337,44 +347,36 @@ extern void __init remap_numa_kva(void);
 #define remap_numa_kva() do {} while (0)
 #endif
 
-static void __init pagetable_init (void)
-{
-	unsigned long vaddr;
-	pgd_t *pgd_base = swapper_pg_dir;
-
+void __init native_pagetable_setup_start(pgd_t *base)
+{
 #ifdef CONFIG_X86_PAE
 	int i;
-	/* Init entries of the first-level page table to the zero page */
-	for (i = 0; i < PTRS_PER_PGD; i++)
-		set_pgd(pgd_base + i, __pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
+
+	/*
+	 * Init entries of the first-level page table to the
+	 * zero page, if they haven't already been set up.
+	 *
+	 * In a normal native boot, we'll be running on a
+	 * pagetable rooted in swapper_pg_dir, but not in PAE
+	 * mode, so this will end up clobbering the mappings
+	 * for the lower 24Mbytes of the address space,
+	 * without affecting the kernel address space.
+	 */
+	for (i = 0; i < USER_PTRS_PER_PGD; i++)
+		set_pgd(&base[i],
+			__pgd(__pa(empty_zero_page) | _PAGE_PRESENT));
+
+	/* Make sure kernel address space is empty so that a pagetable
+	   will be allocated for it. */
+	memset(&base[USER_PTRS_PER_PGD], 0,
+	       KERNEL_PGD_PTRS * sizeof(pgd_t));
 #else
 	paravirt_alloc_pd(__pa(swapper_pg_dir) >> PAGE_SHIFT);
 #endif
-
-	/* Enable PSE if available */
-	if (cpu_has_pse) {
-		set_in_cr4(X86_CR4_PSE);
-	}
-
-	/* Enable PGE if available */
-	if (cpu_has_pge) {
-		set_in_cr4(X86_CR4_PGE);
-		__PAGE_KERNEL |= _PAGE_GLOBAL;
-		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
-	}
-
-	kernel_physical_mapping_init(pgd_base);
-	remap_numa_kva();
-
-	/*
-	 * Fixed mappings, only the page table structure has to be
-	 * created - mappings will be set by set_fixmap():
-	 */
-	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-	page_table_range_init(vaddr, 0, pgd_base);
-
-	permanent_kmaps_init(pgd_base);
-
+}
+
+void __init native_pagetable_setup_done(pgd_t *base)
+{
 #ifdef CONFIG_X86_PAE
 	/*
 	 * Add low memory identity-mappings - SMP needs it when
@@ -383,8 +385,62 @@ static void __init pagetable_init (void)
 	 * All user-space mappings are explicitly cleared after
 	 * SMP startup.
 	 */
-	set_pgd(&pgd_base[0], pgd_base[USER_PTRS_PER_PGD]);
-#endif
+	set_pgd(&base[0], base[USER_PTRS_PER_PGD]);
+#endif
+}
+
+/*
+ * Build a proper pagetable for the kernel mappings.  Up until this
+ * point, we've been running on some set of pagetables constructed by
+ * the boot process.
+ *
+ * If we're booting on native hardware, this will be a pagetable
+ * constructed in arch/i386/kernel/head.S, and not running in PAE mode
+ * (even if we'll end up running in PAE).  The root of the pagetable
+ * will be swapper_pg_dir.
+ *
+ * If we're booting paravirtualized under a hypervisor, then there are
+ * more options: we may already be running PAE, and the pagetable may
+ * or may not be based in swapper_pg_dir.  In any case,
+ * paravirt_pagetable_setup_start() will set up swapper_pg_dir
+ * appropriately for the rest of the initialization to work.
+ *
+ * In general, pagetable_init() assumes that the pagetable may already
+ * be partially populated, and so it avoids stomping on any existing
+ * mappings.
+ */
+static void __init pagetable_init (void)
+{
+	unsigned long vaddr, end;
+	pgd_t *pgd_base = swapper_pg_dir;
+
+	paravirt_pagetable_setup_start(pgd_base);
+
+	/* Enable PSE if available */
+	if (cpu_has_pse)
+		set_in_cr4(X86_CR4_PSE);
+
+	/* Enable PGE if available */
+	if (cpu_has_pge) {
+		set_in_cr4(X86_CR4_PGE);
+		__PAGE_KERNEL |= _PAGE_GLOBAL;
+		__PAGE_KERNEL_EXEC |= _PAGE_GLOBAL;
+	}
+
+	kernel_physical_mapping_init(pgd_base);
+	remap_numa_kva();
+
+	/*
+	 * Fixed mappings, only the page table structure has to be
+	 * created - mappings will be set by set_fixmap():
+	 */
+	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
+	end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
+	page_table_range_init(vaddr, end, pgd_base);
+
+	permanent_kmaps_init(pgd_base);
+
+	paravirt_pagetable_setup_done(pgd_base);
 }
 
 #if defined(CONFIG_SOFTWARE_SUSPEND) || defined(CONFIG_ACPI_SLEEP)
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -2,10 +2,11 @@
 #define __ASM_PARAVIRT_H
 /* Various instructions on x86 need to be replaced for
  * para-virtualization: those hooks are defined here. */
+
+#ifdef CONFIG_PARAVIRT
 #include <linux/stringify.h>
 #include <asm/page.h>
 
-#ifdef CONFIG_PARAVIRT
 /* These are the most performance critical ops, so we want to be able to patch
  * callers */
 #define PARAVIRT_IRQ_DISABLE 0
@@ -48,6 +49,9 @@ struct paravirt_ops
 	void (*arch_setup)(void);
 	char *(*memory_setup)(void);
 	void (*init_IRQ)(void);
+
+	void (*pagetable_setup_start)(pgd_t *pgd_base);
+	void (*pagetable_setup_done)(pgd_t *pgd_base);
 
 	void (*banner)(void);
 
@@ -369,6 +373,17 @@ static inline void setup_secondary_clock
 }
 #endif
 
+static inline void paravirt_pagetable_setup_start(pgd_t *base)
+{
+	if (paravirt_ops.pagetable_setup_start)
+		(*paravirt_ops.pagetable_setup_start)(base);
+}
+
+static inline void paravirt_pagetable_setup_done(pgd_t *base)
+{
+	if (paravirt_ops.pagetable_setup_done)
+		(*paravirt_ops.pagetable_setup_done)(base);
+}
 
 #ifdef CONFIG_SMP
 static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -512,6 +512,22 @@ do {									\
  * tables contain all the necessary information.
  */
 #define update_mmu_cache(vma,address,pte) do { } while (0)
+
+void native_pagetable_setup_start(pgd_t *base);
+void native_pagetable_setup_done(pgd_t *base);
+
+#ifndef CONFIG_PARAVIRT
+static inline void paravirt_pagetable_setup_start(pgd_t *base)
+{
+	native_pagetable_setup_start(base);
+}
+
+static inline void paravirt_pagetable_setup_done(pgd_t *base)
+{
+	native_pagetable_setup_done(base);
+}
+#endif	/* !CONFIG_PARAVIRT */
+
 #endif /* !__ASSEMBLY__ */
 
 #ifdef CONFIG_FLATMEM

-- 

[patch 06/17] Allocate a fixmap slot

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-fixmap.patch --]
[-- Type: text/plain, Size: 1073 bytes --]

Allocate a fixmap slot for use by a paravirt_ops implementation.  This
is intended for early-boot bootstrap mappings.  Once the zones and
allocator have been set up, it would be better to use get_vm_area() to
allocate some virtual space.

Xen uses this to map the hypervisor's shared info page, which doesn't
have a pseudo-physical page number, and therefore can't be mapped
ordinarily.  It is needed early because it contains the vcpu state,
including the interrupt mask.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 include/asm-i386/fixmap.h |    3 +++
 1 file changed, 3 insertions(+)

===================================================================
--- a/include/asm-i386/fixmap.h
+++ b/include/asm-i386/fixmap.h
@@ -86,6 +86,9 @@ enum fixed_addresses {
 #ifdef CONFIG_PCI_MMCONFIG
 	FIX_PCIE_MCFG,
 #endif
+#ifdef CONFIG_PARAVIRT
+	FIX_PARAVIRT_BOOTMAP,
+#endif
 	__end_of_permanent_fixed_addresses,
 	/* temporary boot-time mappings, used before ioremap() is functional */
 #define NR_FIX_BTMAPS	16

-- 

[patch 06/17] Allocate a fixmap slot

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-fixmap.patch --]
[-- Type: text/plain, Size: 1102 bytes --]

Allocate a fixmap slot for use by a paravirt_ops implementation.  This
is intended for early-boot bootstrap mappings.  Once the zones and
allocator have been set up, it would be better to use get_vm_area() to
allocate some virtual space.

Xen uses this to map the hypervisor's shared info page, which doesn't
have a pseudo-physical page number, and therefore can't be mapped
ordinarily.  It is needed early because it contains the vcpu state,
including the interrupt mask.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 include/asm-i386/fixmap.h |    3 +++
 1 file changed, 3 insertions(+)

===================================================================
--- a/include/asm-i386/fixmap.h
+++ b/include/asm-i386/fixmap.h
@@ -86,6 +86,9 @@ enum fixed_addresses {
 #ifdef CONFIG_PCI_MMCONFIG
 	FIX_PCIE_MCFG,
 #endif
+#ifdef CONFIG_PARAVIRT
+	FIX_PARAVIRT_BOOTMAP,
+#endif
 	__end_of_permanent_fixed_addresses,
 	/* temporary boot-time mappings, used before ioremap() is functional */
 #define NR_FIX_BTMAPS	16

-- 

[patch 07/17] Allow paravirt backend to choose kernel PMD sharing

[Jeremy Fitzhardinge]

[-- Attachment #1: shared-kernel-pmd.patch --]
[-- Type: text/plain, Size: 11668 bytes --]

Normally when running in PAE mode, the 4th PMD maps the kernel address
space, which can be shared among all processes (since they all need
the same kernel mappings).

Xen, however, does not allow guests to have the kernel pmd shared
between page tables, so parameterize pgtable.c to allow both modes of
operation.

There are several side-effects of this.  One is that vmalloc will
update the kernel address space mappings, and those updates need to be
propagated into all processes if the kernel mappings are not
intrinsically shared.  In the non-PAE case, this is done by
maintaining a pgd_list of all processes; this list is used when all
process pagetables must be updated.  pgd_list is threaded via
otherwise unused entries in the page structure for the pgd, which
means that the pgd must be page-sized for this to work.

Normally the PAE pgd is only 4x64 byte entries large, but Xen requires
the PAE pgd to page aligned anyway, so this patch forces the pgd to be
page aligned+sized when the kernel pmd is unshared, to accomodate both
these requirements.

Also, since there may be several distinct kernel pmds (if the
user/kernel split is below 3G), there's no point in allocating them
from a slab cache; they're just allocated with get_free_page and
initialized appropriately.  (Of course the could be cached if there is
just a single kernel pmd - which is the default with a 3G user/kernel
split - but it doesn't seem worthwhile to add yet another case into
this code).

[ Many thanks to wli for review comments. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Christoph Lameter <clameter@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
---
 arch/i386/kernel/paravirt.c            |    1 
 arch/i386/mm/fault.c                   |    6 +-
 arch/i386/mm/init.c                    |   18 +++++-
 arch/i386/mm/pageattr.c                |    2 
 arch/i386/mm/pgtable.c                 |   84 ++++++++++++++++++++++++++------
 include/asm-i386/paravirt.h            |    1 
 include/asm-i386/pgtable-2level-defs.h |    2 
 include/asm-i386/pgtable-2level.h      |    2 
 include/asm-i386/pgtable-3level-defs.h |    6 ++
 include/asm-i386/pgtable-3level.h      |    2 
 include/asm-i386/pgtable.h             |    7 ++
 11 files changed, 105 insertions(+), 26 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -604,6 +604,7 @@ struct paravirt_ops paravirt_ops = {
 	.name = "bare hardware",
 	.paravirt_enabled = 0,
 	.kernel_rpl = 0,
+	.shared_kernel_pmd = 1,	/* Only used when CONFIG_X86_PAE is set */
 
  	.patch = native_patch,
 	.banner = default_banner,
===================================================================
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -588,8 +588,7 @@ do_sigbus:
 	force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
 }
 
-#ifndef CONFIG_X86_PAE
-void vmalloc_sync_all(void)
+void _vmalloc_sync_all(void)
 {
 	/*
 	 * Note that races in the updates of insync and start aren't
@@ -600,6 +599,8 @@ void vmalloc_sync_all(void)
 	static DECLARE_BITMAP(insync, PTRS_PER_PGD);
 	static unsigned long start = TASK_SIZE;
 	unsigned long address;
+
+	BUG_ON(SHARED_KERNEL_PMD);
 
 	BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
 	for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
@@ -623,4 +624,3 @@ void vmalloc_sync_all(void)
 			start = address + PGDIR_SIZE;
 	}
 }
-#endif
===================================================================
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -715,6 +715,8 @@ struct kmem_cache *pmd_cache;
 
 void __init pgtable_cache_init(void)
 {
+	size_t pgd_size = PTRS_PER_PGD*sizeof(pgd_t);
+
 	if (PTRS_PER_PMD > 1) {
 		pmd_cache = kmem_cache_create("pmd",
 					PTRS_PER_PMD*sizeof(pmd_t),
@@ -724,13 +726,23 @@ void __init pgtable_cache_init(void)
 					NULL);
 		if (!pmd_cache)
 			panic("pgtable_cache_init(): cannot create pmd cache");
+
+		if (!SHARED_KERNEL_PMD) {
+			/* If we're in PAE mode and have a non-shared
+			   kernel pmd, then the pgd size must be a
+			   page size.  This is because the pgd_list
+			   links through the page structure, so there
+			   can only be one pgd per page for this to
+			   work. */
+			pgd_size = PAGE_SIZE;
+		}
 	}
 	pgd_cache = kmem_cache_create("pgd",
-				PTRS_PER_PGD*sizeof(pgd_t),
-				PTRS_PER_PGD*sizeof(pgd_t),
+				pgd_size,
+				pgd_size,
 				0,
 				pgd_ctor,
-				PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
+				(!SHARED_KERNEL_PMD) ? pgd_dtor : NULL);
 	if (!pgd_cache)
 		panic("pgtable_cache_init(): Cannot create pgd cache");
 }
===================================================================
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -91,7 +91,7 @@ static void set_pmd_pte(pte_t *kpte, uns
 	unsigned long flags;
 
 	set_pte_atomic(kpte, pte); 	/* change init_mm */
-	if (PTRS_PER_PMD > 1)
+	if (SHARED_KERNEL_PMD)
 		return;
 
 	spin_lock_irqsave(&pgd_lock, flags);
===================================================================
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -238,35 +238,56 @@ static inline void pgd_list_del(pgd_t *p
 		set_page_private(next, (unsigned long)pprev);
 }
 
+#if (PTRS_PER_PMD == 1)
+/* Non-PAE pgd constructor */
 void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
 {
 	unsigned long flags;
 
-	if (PTRS_PER_PMD == 1) {
-		memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
-		spin_lock_irqsave(&pgd_lock, flags);
-	}
+	/* !PAE, no pagetable sharing */
+	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
 
 	clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
 			swapper_pg_dir + USER_PTRS_PER_PGD,
 			KERNEL_PGD_PTRS);
 
-	if (PTRS_PER_PMD > 1)
-		return;
+	spin_lock_irqsave(&pgd_lock, flags);
 
 	/* must happen under lock */
 	paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
-			__pa(swapper_pg_dir) >> PAGE_SHIFT,
-			USER_PTRS_PER_PGD, PTRS_PER_PGD - USER_PTRS_PER_PGD);
+				__pa(swapper_pg_dir) >> PAGE_SHIFT,
+				USER_PTRS_PER_PGD,
+				KERNEL_PGD_PTRS);
 
 	pgd_list_add(pgd);
 	spin_unlock_irqrestore(&pgd_lock, flags);
 }
-
-/* never called when PTRS_PER_PMD > 1 */
+#else  /* PTRS_PER_PMD > 1 */
+/* PAE pgd constructor */
+void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+{
+	/* PAE, kernel PMD may be shared */
+
+	if (SHARED_KERNEL_PMD) {
+		clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
+				swapper_pg_dir + USER_PTRS_PER_PGD,
+				KERNEL_PGD_PTRS);
+	} else {
+		unsigned long flags;
+
+		memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+		spin_lock_irqsave(&pgd_lock, flags);
+		pgd_list_add(pgd);
+		spin_unlock_irqrestore(&pgd_lock, flags);
+	}
+}
+#endif	/* PTRS_PER_PMD */
+
 void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)
 {
 	unsigned long flags; /* can be called from interrupt context */
+
+	BUG_ON(SHARED_KERNEL_PMD);
 
 	paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
 	spin_lock_irqsave(&pgd_lock, flags);
@@ -274,6 +295,37 @@ void pgd_dtor(void *pgd, struct kmem_cac
 	spin_unlock_irqrestore(&pgd_lock, flags);
 }
 
+#define UNSHARED_PTRS_PER_PGD				\
+	(SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
+
+/* If we allocate a pmd for part of the kernel address space, then
+   make sure its initialized with the appropriate kernel mappings.
+   Otherwise use a cached zeroed pmd.  */
+static pmd_t *pmd_cache_alloc(int idx)
+{
+	pmd_t *pmd;
+
+	if (idx >= USER_PTRS_PER_PGD) {
+		pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
+
+		if (pmd)
+			memcpy(pmd,
+			       (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
+			       sizeof(pmd_t) * PTRS_PER_PMD);
+	} else
+		pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+
+	return pmd;
+}
+
+static void pmd_cache_free(pmd_t *pmd, int idx)
+{
+	if (idx >= USER_PTRS_PER_PGD)
+		free_page((unsigned long)pmd);
+	else
+		kmem_cache_free(pmd_cache, pmd);
+}
+
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	int i;
@@ -282,10 +334,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 	if (PTRS_PER_PMD == 1 || !pgd)
 		return pgd;
 
-	for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
-		pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+ 	for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
+		pmd_t *pmd = pmd_cache_alloc(i);
+
 		if (!pmd)
 			goto out_oom;
+
 		paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
 		set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
 	}
@@ -296,7 +350,7 @@ out_oom:
 		pgd_t pgdent = pgd[i];
 		void* pmd = (void *)__va(pgd_val(pgdent)-1);
 		paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
-		kmem_cache_free(pmd_cache, pmd);
+		pmd_cache_free(pmd, i);
 	}
 	kmem_cache_free(pgd_cache, pgd);
 	return NULL;
@@ -308,11 +362,11 @@ void pgd_free(pgd_t *pgd)
 
 	/* in the PAE case user pgd entries are overwritten before usage */
 	if (PTRS_PER_PMD > 1)
-		for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+		for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
 			pgd_t pgdent = pgd[i];
 			void* pmd = (void *)__va(pgd_val(pgdent)-1);
 			paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
-			kmem_cache_free(pmd_cache, pmd);
+			pmd_cache_free(pmd, i);
 		}
 	/* in the non-PAE case, free_pgtables() clears user pgd entries */
 	kmem_cache_free(pgd_cache, pgd);
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -34,6 +34,7 @@ struct paravirt_ops
 struct paravirt_ops
 {
 	unsigned int kernel_rpl;
+	int shared_kernel_pmd;
  	int paravirt_enabled;
 	const char *name;
 
===================================================================
--- a/include/asm-i386/pgtable-2level-defs.h
+++ b/include/asm-i386/pgtable-2level-defs.h
@@ -1,5 +1,7 @@
 #ifndef _I386_PGTABLE_2LEVEL_DEFS_H
 #define _I386_PGTABLE_2LEVEL_DEFS_H
+
+#define SHARED_KERNEL_PMD	0
 
 /*
  * traditional i386 two-level paging structure:
===================================================================
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -65,6 +65,4 @@ static inline int pte_exec_kernel(pte_t 
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_low })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
 
-void vmalloc_sync_all(void);
-
 #endif /* _I386_PGTABLE_2LEVEL_H */
===================================================================
--- a/include/asm-i386/pgtable-3level-defs.h
+++ b/include/asm-i386/pgtable-3level-defs.h
@@ -1,5 +1,11 @@
 #ifndef _I386_PGTABLE_3LEVEL_DEFS_H
 #define _I386_PGTABLE_3LEVEL_DEFS_H
+
+#ifdef CONFIG_PARAVIRT
+#define SHARED_KERNEL_PMD	(paravirt_ops.shared_kernel_pmd)
+#else
+#define SHARED_KERNEL_PMD	1
+#endif
 
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
===================================================================
--- a/include/asm-i386/pgtable-3level.h
+++ b/include/asm-i386/pgtable-3level.h
@@ -180,6 +180,4 @@ static inline pmd_t pfn_pmd(unsigned lon
 
 #define __pmd_free_tlb(tlb, x)		do { } while (0)
 
-#define vmalloc_sync_all() ((void)0)
-
 #endif /* _I386_PGTABLE_3LEVEL_H */
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -244,6 +244,13 @@ static inline pte_t pte_mkwrite(pte_t pt
 static inline pte_t pte_mkwrite(pte_t pte)	{ (pte).pte_low |= _PAGE_RW; return pte; }
 static inline pte_t pte_mkhuge(pte_t pte)	{ (pte).pte_low |= _PAGE_PSE; return pte; }
 
+extern void _vmalloc_sync_all(void);
+static inline void vmalloc_sync_all(void)
+{
+	if (!SHARED_KERNEL_PMD)
+		_vmalloc_sync_all();
+}
+
 #ifdef CONFIG_X86_PAE
 # include <asm/pgtable-3level.h>
 #else

-- 

[patch 07/17] Allow paravirt backend to choose kernel PMD sharing

[Jeremy Fitzhardinge]

[-- Attachment #1: shared-kernel-pmd.patch --]
[-- Type: text/plain, Size: 12027 bytes --]

Normally when running in PAE mode, the 4th PMD maps the kernel address
space, which can be shared among all processes (since they all need
the same kernel mappings).

Xen, however, does not allow guests to have the kernel pmd shared
between page tables, so parameterize pgtable.c to allow both modes of
operation.

There are several side-effects of this.  One is that vmalloc will
update the kernel address space mappings, and those updates need to be
propagated into all processes if the kernel mappings are not
intrinsically shared.  In the non-PAE case, this is done by
maintaining a pgd_list of all processes; this list is used when all
process pagetables must be updated.  pgd_list is threaded via
otherwise unused entries in the page structure for the pgd, which
means that the pgd must be page-sized for this to work.

Normally the PAE pgd is only 4x64 byte entries large, but Xen requires
the PAE pgd to page aligned anyway, so this patch forces the pgd to be
page aligned+sized when the kernel pmd is unshared, to accomodate both
these requirements.

Also, since there may be several distinct kernel pmds (if the
user/kernel split is below 3G), there's no point in allocating them
from a slab cache; they're just allocated with get_free_page and
initialized appropriately.  (Of course the could be cached if there is
just a single kernel pmd - which is the default with a 3G user/kernel
split - but it doesn't seem worthwhile to add yet another case into
this code).

[ Many thanks to wli for review comments. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Christoph Lameter <clameter@sgi.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
---
 arch/i386/kernel/paravirt.c            |    1 
 arch/i386/mm/fault.c                   |    6 +-
 arch/i386/mm/init.c                    |   18 +++++-
 arch/i386/mm/pageattr.c                |    2 
 arch/i386/mm/pgtable.c                 |   84 ++++++++++++++++++++++++++------
 include/asm-i386/paravirt.h            |    1 
 include/asm-i386/pgtable-2level-defs.h |    2 
 include/asm-i386/pgtable-2level.h      |    2 
 include/asm-i386/pgtable-3level-defs.h |    6 ++
 include/asm-i386/pgtable-3level.h      |    2 
 include/asm-i386/pgtable.h             |    7 ++
 11 files changed, 105 insertions(+), 26 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -604,6 +604,7 @@ struct paravirt_ops paravirt_ops = {
 	.name = "bare hardware",
 	.paravirt_enabled = 0,
 	.kernel_rpl = 0,
+	.shared_kernel_pmd = 1,	/* Only used when CONFIG_X86_PAE is set */
 
  	.patch = native_patch,
 	.banner = default_banner,
===================================================================
--- a/arch/i386/mm/fault.c
+++ b/arch/i386/mm/fault.c
@@ -588,8 +588,7 @@ do_sigbus:
 	force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk);
 }
 
-#ifndef CONFIG_X86_PAE
-void vmalloc_sync_all(void)
+void _vmalloc_sync_all(void)
 {
 	/*
 	 * Note that races in the updates of insync and start aren't
@@ -600,6 +599,8 @@ void vmalloc_sync_all(void)
 	static DECLARE_BITMAP(insync, PTRS_PER_PGD);
 	static unsigned long start = TASK_SIZE;
 	unsigned long address;
+
+	BUG_ON(SHARED_KERNEL_PMD);
 
 	BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK);
 	for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) {
@@ -623,4 +624,3 @@ void vmalloc_sync_all(void)
 			start = address + PGDIR_SIZE;
 	}
 }
-#endif
===================================================================
--- a/arch/i386/mm/init.c
+++ b/arch/i386/mm/init.c
@@ -715,6 +715,8 @@ struct kmem_cache *pmd_cache;
 
 void __init pgtable_cache_init(void)
 {
+	size_t pgd_size = PTRS_PER_PGD*sizeof(pgd_t);
+
 	if (PTRS_PER_PMD > 1) {
 		pmd_cache = kmem_cache_create("pmd",
 					PTRS_PER_PMD*sizeof(pmd_t),
@@ -724,13 +726,23 @@ void __init pgtable_cache_init(void)
 					NULL);
 		if (!pmd_cache)
 			panic("pgtable_cache_init(): cannot create pmd cache");
+
+		if (!SHARED_KERNEL_PMD) {
+			/* If we're in PAE mode and have a non-shared
+			   kernel pmd, then the pgd size must be a
+			   page size.  This is because the pgd_list
+			   links through the page structure, so there
+			   can only be one pgd per page for this to
+			   work. */
+			pgd_size = PAGE_SIZE;
+		}
 	}
 	pgd_cache = kmem_cache_create("pgd",
-				PTRS_PER_PGD*sizeof(pgd_t),
-				PTRS_PER_PGD*sizeof(pgd_t),
+				pgd_size,
+				pgd_size,
 				0,
 				pgd_ctor,
-				PTRS_PER_PMD == 1 ? pgd_dtor : NULL);
+				(!SHARED_KERNEL_PMD) ? pgd_dtor : NULL);
 	if (!pgd_cache)
 		panic("pgtable_cache_init(): Cannot create pgd cache");
 }
===================================================================
--- a/arch/i386/mm/pageattr.c
+++ b/arch/i386/mm/pageattr.c
@@ -91,7 +91,7 @@ static void set_pmd_pte(pte_t *kpte, uns
 	unsigned long flags;
 
 	set_pte_atomic(kpte, pte); 	/* change init_mm */
-	if (PTRS_PER_PMD > 1)
+	if (SHARED_KERNEL_PMD)
 		return;
 
 	spin_lock_irqsave(&pgd_lock, flags);
===================================================================
--- a/arch/i386/mm/pgtable.c
+++ b/arch/i386/mm/pgtable.c
@@ -238,35 +238,56 @@ static inline void pgd_list_del(pgd_t *p
 		set_page_private(next, (unsigned long)pprev);
 }
 
+#if (PTRS_PER_PMD == 1)
+/* Non-PAE pgd constructor */
 void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
 {
 	unsigned long flags;
 
-	if (PTRS_PER_PMD == 1) {
-		memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
-		spin_lock_irqsave(&pgd_lock, flags);
-	}
+	/* !PAE, no pagetable sharing */
+	memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
 
 	clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
 			swapper_pg_dir + USER_PTRS_PER_PGD,
 			KERNEL_PGD_PTRS);
 
-	if (PTRS_PER_PMD > 1)
-		return;
+	spin_lock_irqsave(&pgd_lock, flags);
 
 	/* must happen under lock */
 	paravirt_alloc_pd_clone(__pa(pgd) >> PAGE_SHIFT,
-			__pa(swapper_pg_dir) >> PAGE_SHIFT,
-			USER_PTRS_PER_PGD, PTRS_PER_PGD - USER_PTRS_PER_PGD);
+				__pa(swapper_pg_dir) >> PAGE_SHIFT,
+				USER_PTRS_PER_PGD,
+				KERNEL_PGD_PTRS);
 
 	pgd_list_add(pgd);
 	spin_unlock_irqrestore(&pgd_lock, flags);
 }
-
-/* never called when PTRS_PER_PMD > 1 */
+#else  /* PTRS_PER_PMD > 1 */
+/* PAE pgd constructor */
+void pgd_ctor(void *pgd, struct kmem_cache *cache, unsigned long unused)
+{
+	/* PAE, kernel PMD may be shared */
+
+	if (SHARED_KERNEL_PMD) {
+		clone_pgd_range((pgd_t *)pgd + USER_PTRS_PER_PGD,
+				swapper_pg_dir + USER_PTRS_PER_PGD,
+				KERNEL_PGD_PTRS);
+	} else {
+		unsigned long flags;
+
+		memset(pgd, 0, USER_PTRS_PER_PGD*sizeof(pgd_t));
+		spin_lock_irqsave(&pgd_lock, flags);
+		pgd_list_add(pgd);
+		spin_unlock_irqrestore(&pgd_lock, flags);
+	}
+}
+#endif	/* PTRS_PER_PMD */
+
 void pgd_dtor(void *pgd, struct kmem_cache *cache, unsigned long unused)
 {
 	unsigned long flags; /* can be called from interrupt context */
+
+	BUG_ON(SHARED_KERNEL_PMD);
 
 	paravirt_release_pd(__pa(pgd) >> PAGE_SHIFT);
 	spin_lock_irqsave(&pgd_lock, flags);
@@ -274,6 +295,37 @@ void pgd_dtor(void *pgd, struct kmem_cac
 	spin_unlock_irqrestore(&pgd_lock, flags);
 }
 
+#define UNSHARED_PTRS_PER_PGD				\
+	(SHARED_KERNEL_PMD ? USER_PTRS_PER_PGD : PTRS_PER_PGD)
+
+/* If we allocate a pmd for part of the kernel address space, then
+   make sure its initialized with the appropriate kernel mappings.
+   Otherwise use a cached zeroed pmd.  */
+static pmd_t *pmd_cache_alloc(int idx)
+{
+	pmd_t *pmd;
+
+	if (idx >= USER_PTRS_PER_PGD) {
+		pmd = (pmd_t *)__get_free_page(GFP_KERNEL);
+
+		if (pmd)
+			memcpy(pmd,
+			       (void *)pgd_page_vaddr(swapper_pg_dir[idx]),
+			       sizeof(pmd_t) * PTRS_PER_PMD);
+	} else
+		pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+
+	return pmd;
+}
+
+static void pmd_cache_free(pmd_t *pmd, int idx)
+{
+	if (idx >= USER_PTRS_PER_PGD)
+		free_page((unsigned long)pmd);
+	else
+		kmem_cache_free(pmd_cache, pmd);
+}
+
 pgd_t *pgd_alloc(struct mm_struct *mm)
 {
 	int i;
@@ -282,10 +334,12 @@ pgd_t *pgd_alloc(struct mm_struct *mm)
 	if (PTRS_PER_PMD == 1 || !pgd)
 		return pgd;
 
-	for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
-		pmd_t *pmd = kmem_cache_alloc(pmd_cache, GFP_KERNEL);
+ 	for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
+		pmd_t *pmd = pmd_cache_alloc(i);
+
 		if (!pmd)
 			goto out_oom;
+
 		paravirt_alloc_pd(__pa(pmd) >> PAGE_SHIFT);
 		set_pgd(&pgd[i], __pgd(1 + __pa(pmd)));
 	}
@@ -296,7 +350,7 @@ out_oom:
 		pgd_t pgdent = pgd[i];
 		void* pmd = (void *)__va(pgd_val(pgdent)-1);
 		paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
-		kmem_cache_free(pmd_cache, pmd);
+		pmd_cache_free(pmd, i);
 	}
 	kmem_cache_free(pgd_cache, pgd);
 	return NULL;
@@ -308,11 +362,11 @@ void pgd_free(pgd_t *pgd)
 
 	/* in the PAE case user pgd entries are overwritten before usage */
 	if (PTRS_PER_PMD > 1)
-		for (i = 0; i < USER_PTRS_PER_PGD; ++i) {
+		for (i = 0; i < UNSHARED_PTRS_PER_PGD; ++i) {
 			pgd_t pgdent = pgd[i];
 			void* pmd = (void *)__va(pgd_val(pgdent)-1);
 			paravirt_release_pd(__pa(pmd) >> PAGE_SHIFT);
-			kmem_cache_free(pmd_cache, pmd);
+			pmd_cache_free(pmd, i);
 		}
 	/* in the non-PAE case, free_pgtables() clears user pgd entries */
 	kmem_cache_free(pgd_cache, pgd);
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -34,6 +34,7 @@ struct paravirt_ops
 struct paravirt_ops
 {
 	unsigned int kernel_rpl;
+	int shared_kernel_pmd;
  	int paravirt_enabled;
 	const char *name;
 
===================================================================
--- a/include/asm-i386/pgtable-2level-defs.h
+++ b/include/asm-i386/pgtable-2level-defs.h
@@ -1,5 +1,7 @@
 #ifndef _I386_PGTABLE_2LEVEL_DEFS_H
 #define _I386_PGTABLE_2LEVEL_DEFS_H
+
+#define SHARED_KERNEL_PMD	0
 
 /*
  * traditional i386 two-level paging structure:
===================================================================
--- a/include/asm-i386/pgtable-2level.h
+++ b/include/asm-i386/pgtable-2level.h
@@ -65,6 +65,4 @@ static inline int pte_exec_kernel(pte_t 
 #define __pte_to_swp_entry(pte)		((swp_entry_t) { (pte).pte_low })
 #define __swp_entry_to_pte(x)		((pte_t) { (x).val })
 
-void vmalloc_sync_all(void);
-
 #endif /* _I386_PGTABLE_2LEVEL_H */
===================================================================
--- a/include/asm-i386/pgtable-3level-defs.h
+++ b/include/asm-i386/pgtable-3level-defs.h
@@ -1,5 +1,11 @@
 #ifndef _I386_PGTABLE_3LEVEL_DEFS_H
 #define _I386_PGTABLE_3LEVEL_DEFS_H
+
+#ifdef CONFIG_PARAVIRT
+#define SHARED_KERNEL_PMD	(paravirt_ops.shared_kernel_pmd)
+#else
+#define SHARED_KERNEL_PMD	1
+#endif
 
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
===================================================================
--- a/include/asm-i386/pgtable-3level.h
+++ b/include/asm-i386/pgtable-3level.h
@@ -180,6 +180,4 @@ static inline pmd_t pfn_pmd(unsigned lon
 
 #define __pmd_free_tlb(tlb, x)		do { } while (0)
 
-#define vmalloc_sync_all() ((void)0)
-
 #endif /* _I386_PGTABLE_3LEVEL_H */
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -244,6 +244,13 @@ static inline pte_t pte_mkwrite(pte_t pt
 static inline pte_t pte_mkwrite(pte_t pte)	{ (pte).pte_low |= _PAGE_RW; return pte; }
 static inline pte_t pte_mkhuge(pte_t pte)	{ (pte).pte_low |= _PAGE_PSE; return pte; }
 
+extern void _vmalloc_sync_all(void);
+static inline void vmalloc_sync_all(void)
+{
+	if (!SHARED_KERNEL_PMD)
+		_vmalloc_sync_all();
+}
+
 #ifdef CONFIG_X86_PAE
 # include <asm/pgtable-3level.h>
 #else

-- 

[patch 08/17] add hooks to intercept mm creation and destruction

[Jeremy Fitzhardinge]

[-- Attachment #1: mm-lifetime-hooks.patch --]
[-- Type: text/plain, Size: 14279 bytes --]

Add hooks to allow a paravirt implementation to track the lifetime of
an mm.  Paravirtualization requires three hooks, but only two are
needed in common code.  They are:

arch_dup_mmap, which is called when a new mmap is created at fork

arch_exit_mmap, which is called when the last process reference to an
  mm is dropped, which typically happens on exit and exec.

The third hook is activate_mm, which is called from the arch-specific
activate_mm() macro/function, and so doesn't need stub versions for
other architectures.  It's called when an mm is first used.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-arch@vger.kernel.org
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c         |    4 ++++
 include/asm-alpha/mmu_context.h     |    1 +
 include/asm-arm/mmu_context.h       |    1 +
 include/asm-arm26/mmu_context.h     |    2 ++
 include/asm-avr32/mmu_context.h     |    1 +
 include/asm-cris/mmu_context.h      |    2 ++
 include/asm-frv/mmu_context.h       |    1 +
 include/asm-generic/mm_hooks.h      |   18 ++++++++++++++++++
 include/asm-h8300/mmu_context.h     |    1 +
 include/asm-i386/mmu_context.h      |   17 +++++++++++++++--
 include/asm-i386/paravirt.h         |   23 +++++++++++++++++++++++
 include/asm-ia64/mmu_context.h      |    1 +
 include/asm-m32r/mmu_context.h      |    1 +
 include/asm-m68k/mmu_context.h      |    1 +
 include/asm-m68knommu/mmu_context.h |    1 +
 include/asm-mips/mmu_context.h      |    1 +
 include/asm-parisc/mmu_context.h    |    1 +
 include/asm-powerpc/mmu_context.h   |    1 +
 include/asm-ppc/mmu_context.h       |    1 +
 include/asm-s390/mmu_context.h      |    2 ++
 include/asm-sh/mmu_context.h        |    1 +
 include/asm-sh64/mmu_context.h      |    2 +-
 include/asm-sparc/mmu_context.h     |    2 ++
 include/asm-sparc64/mmu_context.h   |    1 +
 include/asm-um/mmu_context.h        |    2 ++
 include/asm-v850/mmu_context.h      |    2 ++
 include/asm-x86_64/mmu_context.h    |    1 +
 include/asm-xtensa/mmu_context.h    |    1 +
 kernel/fork.c                       |    2 ++
 mm/mmap.c                           |    4 ++++
 30 files changed, 96 insertions(+), 3 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -520,6 +520,10 @@ struct paravirt_ops paravirt_ops = {
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
 
+	.dup_mmap = paravirt_nop,
+	.exit_mmap = paravirt_nop,
+	.activate_mm = paravirt_nop,
+
 	.startup_ipi_hook = paravirt_nop,
 };
 
===================================================================
--- a/include/asm-alpha/mmu_context.h
+++ b/include/asm-alpha/mmu_context.h
@@ -10,6 +10,7 @@
 #include <asm/system.h>
 #include <asm/machvec.h>
 #include <asm/compiler.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Force a context reload. This is needed when we change the page
===================================================================
--- a/include/asm-arm/mmu_context.h
+++ b/include/asm-arm/mmu_context.h
@@ -16,6 +16,7 @@
 #include <linux/compiler.h>
 #include <asm/cacheflush.h>
 #include <asm/proc-fns.h>
+#include <asm-generic/mm_hooks.h>
 
 void __check_kvm_seq(struct mm_struct *mm);
 
===================================================================
--- a/include/asm-arm26/mmu_context.h
+++ b/include/asm-arm26/mmu_context.h
@@ -12,6 +12,8 @@
  */
 #ifndef __ASM_ARM_MMU_CONTEXT_H
 #define __ASM_ARM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 #define init_new_context(tsk,mm)	0
 #define destroy_context(mm)		do { } while(0)
===================================================================
--- a/include/asm-avr32/mmu_context.h
+++ b/include/asm-avr32/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/tlbflush.h>
 #include <asm/pgalloc.h>
 #include <asm/sysreg.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * The MMU "context" consists of two things:
===================================================================
--- a/include/asm-cris/mmu_context.h
+++ b/include/asm-cris/mmu_context.h
@@ -1,5 +1,7 @@
 #ifndef __CRIS_MMU_CONTEXT_H
 #define __CRIS_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
 extern void get_mmu_context(struct mm_struct *mm);
===================================================================
--- a/include/asm-frv/mmu_context.h
+++ b/include/asm-frv/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- /dev/null
+++ b/include/asm-generic/mm_hooks.h
@@ -0,0 +1,18 @@
+/*
+ * Define generic no-op hooks for arch_dup_mmap and arch_exit_mmap, to
+ * be included in asm-FOO/mmu_context.h for any arch FOO which doesn't
+ * need to hook these.
+ */
+#ifndef _ASM_GENERIC_MM_HOOKS_H
+#define _ASM_GENERIC_MM_HOOKS_H
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+				 struct mm_struct *mm)
+{
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+#endif	/* _ASM_GENERIC_MM_HOOKS_H */
===================================================================
--- a/include/asm-h8300/mmu_context.h
+++ b/include/asm-h8300/mmu_context.h
@@ -4,6 +4,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -5,6 +5,16 @@
 #include <asm/atomic.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
+#include <asm/paravirt.h>
+#ifndef CONFIG_PARAVIRT
+#include <asm-generic/mm_hooks.h>
+
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+					struct mm_struct *next)
+{
+}
+#endif	/* !CONFIG_PARAVIRT */
+
 
 /*
  * Used for LDT copy/destruction.
@@ -65,7 +75,10 @@ static inline void switch_mm(struct mm_s
 #define deactivate_mm(tsk, mm)			\
 	asm("movl %0,%%gs": :"r" (0));
 
-#define activate_mm(prev, next) \
-	switch_mm((prev),(next),NULL)
+#define activate_mm(prev, next)				\
+	do {						\
+		paravirt_activate_mm(prev, next);	\
+		switch_mm((prev),(next),NULL);		\
+	} while(0);
 
 #endif
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -119,6 +119,12 @@ struct paravirt_ops
 
 	void (*io_delay)(void);
 
+	void (*activate_mm)(struct mm_struct *prev,
+			    struct mm_struct *next);
+	void (*dup_mmap)(struct mm_struct *oldmm,
+			 struct mm_struct *mm);
+	void (*exit_mmap)(struct mm_struct *mm);
+
 #ifdef CONFIG_X86_LOCAL_APIC
 	void (*apic_write)(unsigned long reg, unsigned long v);
 	void (*apic_write_atomic)(unsigned long reg, unsigned long v);
@@ -394,6 +400,23 @@ static inline void startup_ipi_hook(int 
 }
 #endif
 
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+					struct mm_struct *next)
+{
+	paravirt_ops.activate_mm(prev, next);
+}
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+				 struct mm_struct *mm)
+{
+	paravirt_ops.dup_mmap(oldmm, mm);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+	paravirt_ops.exit_mmap(mm);
+}
+
 #define __flush_tlb() paravirt_ops.flush_tlb_user()
 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
===================================================================
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -29,6 +29,7 @@
 #include <linux/spinlock.h>
 
 #include <asm/processor.h>
+#include <asm-generic/mm_hooks.h>
 
 struct ia64_ctx {
 	spinlock_t lock;
===================================================================
--- a/include/asm-m32r/mmu_context.h
+++ b/include/asm-m32r/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/pgalloc.h>
 #include <asm/mmu.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Cache of MMU context last used.
===================================================================
--- a/include/asm-m68k/mmu_context.h
+++ b/include/asm-m68k/mmu_context.h
@@ -1,6 +1,7 @@
 #ifndef __M68K_MMU_CONTEXT_H
 #define __M68K_MMU_CONTEXT_H
 
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-m68knommu/mmu_context.h
+++ b/include/asm-m68knommu/mmu_context.h
@@ -4,6 +4,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-mips/mmu_context.h
+++ b/include/asm-mips/mmu_context.h
@@ -20,6 +20,7 @@
 #include <asm/mipsmtregs.h>
 #include <asm/smtc.h>
 #endif /* SMTC */
+#include <asm-generic/mm_hooks.h>
 
 /*
  * For the fast tlb miss handlers, we keep a per cpu array of pointers
===================================================================
--- a/include/asm-parisc/mmu_context.h
+++ b/include/asm-parisc/mmu_context.h
@@ -5,6 +5,7 @@
 #include <asm/atomic.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-powerpc/mmu_context.h
+++ b/include/asm-powerpc/mmu_context.h
@@ -10,6 +10,7 @@
 #include <linux/mm.h>	
 #include <asm/mmu.h>	
 #include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Copyright (C) 2001 PPC 64 Team, IBM Corp
===================================================================
--- a/include/asm-ppc/mmu_context.h
+++ b/include/asm-ppc/mmu_context.h
@@ -6,6 +6,7 @@
 #include <asm/bitops.h>
 #include <asm/mmu.h>
 #include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs
===================================================================
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -10,6 +10,8 @@
 #define __S390_MMU_CONTEXT_H
 
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
+
 /*
  * get a new mmu context.. S390 don't know about contexts.
  */
===================================================================
--- a/include/asm-sh/mmu_context.h
+++ b/include/asm-sh/mmu_context.h
@@ -12,6 +12,7 @@
 #include <asm/tlbflush.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * The MMU "context" consists of two things:
===================================================================
--- a/include/asm-sh64/mmu_context.h
+++ b/include/asm-sh64/mmu_context.h
@@ -27,7 +27,7 @@ extern unsigned long mmu_context_cache;
 extern unsigned long mmu_context_cache;
 
 #include <asm/page.h>
-
+#include <asm-generic/mm_hooks.h>
 
 /* Current mm's pgd */
 extern pgd_t *mmu_pdtp_cache;
===================================================================
--- a/include/asm-sparc/mmu_context.h
+++ b/include/asm-sparc/mmu_context.h
@@ -4,6 +4,8 @@
 #include <asm/btfixup.h>
 
 #ifndef __ASSEMBLY__
+
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-sparc64/mmu_context.h
+++ b/include/asm-sparc64/mmu_context.h
@@ -9,6 +9,7 @@
 #include <linux/spinlock.h>
 #include <asm/system.h>
 #include <asm/spitfire.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-um/mmu_context.h
+++ b/include/asm-um/mmu_context.h
@@ -5,6 +5,8 @@
 
 #ifndef __UM_MMU_CONTEXT_H
 #define __UM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 #include "linux/sched.h"
 #include "choose-mode.h"
===================================================================
--- a/include/asm-v850/mmu_context.h
+++ b/include/asm-v850/mmu_context.h
@@ -1,5 +1,7 @@
 #ifndef __V850_MMU_CONTEXT_H__
 #define __V850_MMU_CONTEXT_H__
+
+#include <asm-generic/mm_hooks.h>
 
 #define destroy_context(mm)		((void)0)
 #define init_new_context(tsk,mm)	0
===================================================================
--- a/include/asm-x86_64/mmu_context.h
+++ b/include/asm-x86_64/mmu_context.h
@@ -7,6 +7,7 @@
 #include <asm/pda.h>
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * possibly do the LDT unload here?
===================================================================
--- a/include/asm-xtensa/mmu_context.h
+++ b/include/asm-xtensa/mmu_context.h
@@ -18,6 +18,7 @@
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 #define XCHAL_MMU_ASID_BITS	8
 
===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -286,6 +286,8 @@ static inline int dup_mmap(struct mm_str
 		if (retval)
 			goto out;
 	}
+	/* a new mm has just been created */
+	arch_dup_mmap(oldmm, mm);
 	retval = 0;
 out:
 	up_write(&mm->mmap_sem);
===================================================================
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -29,6 +29,7 @@
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
 #include <asm/tlb.h>
+#include <asm/mmu_context.h>
 
 #ifndef arch_mmap_check
 #define arch_mmap_check(addr, len, flags)	(0)
@@ -1976,6 +1977,9 @@ void exit_mmap(struct mm_struct *mm)
 	struct vm_area_struct *vma = mm->mmap;
 	unsigned long nr_accounted = 0;
 	unsigned long end;
+
+	/* mm's last user has gone, and its about to be pulled down */
+	arch_exit_mmap(mm);
 
 	lru_add_drain();
 	flush_cache_mm(mm);

-- 

[patch 08/17] add hooks to intercept mm creation and destruction

[Jeremy Fitzhardinge]

[-- Attachment #1: mm-lifetime-hooks.patch --]
[-- Type: text/plain, Size: 14740 bytes --]

Add hooks to allow a paravirt implementation to track the lifetime of
an mm.  Paravirtualization requires three hooks, but only two are
needed in common code.  They are:

arch_dup_mmap, which is called when a new mmap is created at fork

arch_exit_mmap, which is called when the last process reference to an
  mm is dropped, which typically happens on exit and exec.

The third hook is activate_mm, which is called from the arch-specific
activate_mm() macro/function, and so doesn't need stub versions for
other architectures.  It's called when an mm is first used.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: linux-arch@vger.kernel.org
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>

---
 arch/i386/kernel/paravirt.c         |    4 ++++
 include/asm-alpha/mmu_context.h     |    1 +
 include/asm-arm/mmu_context.h       |    1 +
 include/asm-arm26/mmu_context.h     |    2 ++
 include/asm-avr32/mmu_context.h     |    1 +
 include/asm-cris/mmu_context.h      |    2 ++
 include/asm-frv/mmu_context.h       |    1 +
 include/asm-generic/mm_hooks.h      |   18 ++++++++++++++++++
 include/asm-h8300/mmu_context.h     |    1 +
 include/asm-i386/mmu_context.h      |   17 +++++++++++++++--
 include/asm-i386/paravirt.h         |   23 +++++++++++++++++++++++
 include/asm-ia64/mmu_context.h      |    1 +
 include/asm-m32r/mmu_context.h      |    1 +
 include/asm-m68k/mmu_context.h      |    1 +
 include/asm-m68knommu/mmu_context.h |    1 +
 include/asm-mips/mmu_context.h      |    1 +
 include/asm-parisc/mmu_context.h    |    1 +
 include/asm-powerpc/mmu_context.h   |    1 +
 include/asm-ppc/mmu_context.h       |    1 +
 include/asm-s390/mmu_context.h      |    2 ++
 include/asm-sh/mmu_context.h        |    1 +
 include/asm-sh64/mmu_context.h      |    2 +-
 include/asm-sparc/mmu_context.h     |    2 ++
 include/asm-sparc64/mmu_context.h   |    1 +
 include/asm-um/mmu_context.h        |    2 ++
 include/asm-v850/mmu_context.h      |    2 ++
 include/asm-x86_64/mmu_context.h    |    1 +
 include/asm-xtensa/mmu_context.h    |    1 +
 kernel/fork.c                       |    2 ++
 mm/mmap.c                           |    4 ++++
 30 files changed, 96 insertions(+), 3 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -520,6 +520,10 @@ struct paravirt_ops paravirt_ops = {
 	.irq_enable_sysexit = native_irq_enable_sysexit,
 	.iret = native_iret,
 
+	.dup_mmap = paravirt_nop,
+	.exit_mmap = paravirt_nop,
+	.activate_mm = paravirt_nop,
+
 	.startup_ipi_hook = paravirt_nop,
 };
 
===================================================================
--- a/include/asm-alpha/mmu_context.h
+++ b/include/asm-alpha/mmu_context.h
@@ -10,6 +10,7 @@
 #include <asm/system.h>
 #include <asm/machvec.h>
 #include <asm/compiler.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Force a context reload. This is needed when we change the page
===================================================================
--- a/include/asm-arm/mmu_context.h
+++ b/include/asm-arm/mmu_context.h
@@ -16,6 +16,7 @@
 #include <linux/compiler.h>
 #include <asm/cacheflush.h>
 #include <asm/proc-fns.h>
+#include <asm-generic/mm_hooks.h>
 
 void __check_kvm_seq(struct mm_struct *mm);
 
===================================================================
--- a/include/asm-arm26/mmu_context.h
+++ b/include/asm-arm26/mmu_context.h
@@ -12,6 +12,8 @@
  */
 #ifndef __ASM_ARM_MMU_CONTEXT_H
 #define __ASM_ARM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 #define init_new_context(tsk,mm)	0
 #define destroy_context(mm)		do { } while(0)
===================================================================
--- a/include/asm-avr32/mmu_context.h
+++ b/include/asm-avr32/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/tlbflush.h>
 #include <asm/pgalloc.h>
 #include <asm/sysreg.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * The MMU "context" consists of two things:
===================================================================
--- a/include/asm-cris/mmu_context.h
+++ b/include/asm-cris/mmu_context.h
@@ -1,5 +1,7 @@
 #ifndef __CRIS_MMU_CONTEXT_H
 #define __CRIS_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
 extern void get_mmu_context(struct mm_struct *mm);
===================================================================
--- a/include/asm-frv/mmu_context.h
+++ b/include/asm-frv/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- /dev/null
+++ b/include/asm-generic/mm_hooks.h
@@ -0,0 +1,18 @@
+/*
+ * Define generic no-op hooks for arch_dup_mmap and arch_exit_mmap, to
+ * be included in asm-FOO/mmu_context.h for any arch FOO which doesn't
+ * need to hook these.
+ */
+#ifndef _ASM_GENERIC_MM_HOOKS_H
+#define _ASM_GENERIC_MM_HOOKS_H
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+				 struct mm_struct *mm)
+{
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+#endif	/* _ASM_GENERIC_MM_HOOKS_H */
===================================================================
--- a/include/asm-h8300/mmu_context.h
+++ b/include/asm-h8300/mmu_context.h
@@ -4,6 +4,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -5,6 +5,16 @@
 #include <asm/atomic.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
+#include <asm/paravirt.h>
+#ifndef CONFIG_PARAVIRT
+#include <asm-generic/mm_hooks.h>
+
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+					struct mm_struct *next)
+{
+}
+#endif	/* !CONFIG_PARAVIRT */
+
 
 /*
  * Used for LDT copy/destruction.
@@ -65,7 +75,10 @@ static inline void switch_mm(struct mm_s
 #define deactivate_mm(tsk, mm)			\
 	asm("movl %0,%%gs": :"r" (0));
 
-#define activate_mm(prev, next) \
-	switch_mm((prev),(next),NULL)
+#define activate_mm(prev, next)				\
+	do {						\
+		paravirt_activate_mm(prev, next);	\
+		switch_mm((prev),(next),NULL);		\
+	} while(0);
 
 #endif
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -119,6 +119,12 @@ struct paravirt_ops
 
 	void (*io_delay)(void);
 
+	void (*activate_mm)(struct mm_struct *prev,
+			    struct mm_struct *next);
+	void (*dup_mmap)(struct mm_struct *oldmm,
+			 struct mm_struct *mm);
+	void (*exit_mmap)(struct mm_struct *mm);
+
 #ifdef CONFIG_X86_LOCAL_APIC
 	void (*apic_write)(unsigned long reg, unsigned long v);
 	void (*apic_write_atomic)(unsigned long reg, unsigned long v);
@@ -394,6 +400,23 @@ static inline void startup_ipi_hook(int 
 }
 #endif
 
+static inline void paravirt_activate_mm(struct mm_struct *prev,
+					struct mm_struct *next)
+{
+	paravirt_ops.activate_mm(prev, next);
+}
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+				 struct mm_struct *mm)
+{
+	paravirt_ops.dup_mmap(oldmm, mm);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+	paravirt_ops.exit_mmap(mm);
+}
+
 #define __flush_tlb() paravirt_ops.flush_tlb_user()
 #define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
 #define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
===================================================================
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -29,6 +29,7 @@
 #include <linux/spinlock.h>
 
 #include <asm/processor.h>
+#include <asm-generic/mm_hooks.h>
 
 struct ia64_ctx {
 	spinlock_t lock;
===================================================================
--- a/include/asm-m32r/mmu_context.h
+++ b/include/asm-m32r/mmu_context.h
@@ -15,6 +15,7 @@
 #include <asm/pgalloc.h>
 #include <asm/mmu.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Cache of MMU context last used.
===================================================================
--- a/include/asm-m68k/mmu_context.h
+++ b/include/asm-m68k/mmu_context.h
@@ -1,6 +1,7 @@
 #ifndef __M68K_MMU_CONTEXT_H
 #define __M68K_MMU_CONTEXT_H
 
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-m68knommu/mmu_context.h
+++ b/include/asm-m68knommu/mmu_context.h
@@ -4,6 +4,7 @@
 #include <asm/setup.h>
 #include <asm/page.h>
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-mips/mmu_context.h
+++ b/include/asm-mips/mmu_context.h
@@ -20,6 +20,7 @@
 #include <asm/mipsmtregs.h>
 #include <asm/smtc.h>
 #endif /* SMTC */
+#include <asm-generic/mm_hooks.h>
 
 /*
  * For the fast tlb miss handlers, we keep a per cpu array of pointers
===================================================================
--- a/include/asm-parisc/mmu_context.h
+++ b/include/asm-parisc/mmu_context.h
@@ -5,6 +5,7 @@
 #include <asm/atomic.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-powerpc/mmu_context.h
+++ b/include/asm-powerpc/mmu_context.h
@@ -10,6 +10,7 @@
 #include <linux/mm.h>	
 #include <asm/mmu.h>	
 #include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * Copyright (C) 2001 PPC 64 Team, IBM Corp
===================================================================
--- a/include/asm-ppc/mmu_context.h
+++ b/include/asm-ppc/mmu_context.h
@@ -6,6 +6,7 @@
 #include <asm/bitops.h>
 #include <asm/mmu.h>
 #include <asm/cputable.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs
===================================================================
--- a/include/asm-s390/mmu_context.h
+++ b/include/asm-s390/mmu_context.h
@@ -10,6 +10,8 @@
 #define __S390_MMU_CONTEXT_H
 
 #include <asm/pgalloc.h>
+#include <asm-generic/mm_hooks.h>
+
 /*
  * get a new mmu context.. S390 don't know about contexts.
  */
===================================================================
--- a/include/asm-sh/mmu_context.h
+++ b/include/asm-sh/mmu_context.h
@@ -12,6 +12,7 @@
 #include <asm/tlbflush.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * The MMU "context" consists of two things:
===================================================================
--- a/include/asm-sh64/mmu_context.h
+++ b/include/asm-sh64/mmu_context.h
@@ -27,7 +27,7 @@ extern unsigned long mmu_context_cache;
 extern unsigned long mmu_context_cache;
 
 #include <asm/page.h>
-
+#include <asm-generic/mm_hooks.h>
 
 /* Current mm's pgd */
 extern pgd_t *mmu_pdtp_cache;
===================================================================
--- a/include/asm-sparc/mmu_context.h
+++ b/include/asm-sparc/mmu_context.h
@@ -4,6 +4,8 @@
 #include <asm/btfixup.h>
 
 #ifndef __ASSEMBLY__
+
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-sparc64/mmu_context.h
+++ b/include/asm-sparc64/mmu_context.h
@@ -9,6 +9,7 @@
 #include <linux/spinlock.h>
 #include <asm/system.h>
 #include <asm/spitfire.h>
+#include <asm-generic/mm_hooks.h>
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {
===================================================================
--- a/include/asm-um/mmu_context.h
+++ b/include/asm-um/mmu_context.h
@@ -5,6 +5,8 @@
 
 #ifndef __UM_MMU_CONTEXT_H
 #define __UM_MMU_CONTEXT_H
+
+#include <asm-generic/mm_hooks.h>
 
 #include "linux/sched.h"
 #include "choose-mode.h"
===================================================================
--- a/include/asm-v850/mmu_context.h
+++ b/include/asm-v850/mmu_context.h
@@ -1,5 +1,7 @@
 #ifndef __V850_MMU_CONTEXT_H__
 #define __V850_MMU_CONTEXT_H__
+
+#include <asm-generic/mm_hooks.h>
 
 #define destroy_context(mm)		((void)0)
 #define init_new_context(tsk,mm)	0
===================================================================
--- a/include/asm-x86_64/mmu_context.h
+++ b/include/asm-x86_64/mmu_context.h
@@ -7,6 +7,7 @@
 #include <asm/pda.h>
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 /*
  * possibly do the LDT unload here?
===================================================================
--- a/include/asm-xtensa/mmu_context.h
+++ b/include/asm-xtensa/mmu_context.h
@@ -18,6 +18,7 @@
 #include <asm/pgtable.h>
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
 
 #define XCHAL_MMU_ASID_BITS	8
 
===================================================================
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -286,6 +286,8 @@ static inline int dup_mmap(struct mm_str
 		if (retval)
 			goto out;
 	}
+	/* a new mm has just been created */
+	arch_dup_mmap(oldmm, mm);
 	retval = 0;
 out:
 	up_write(&mm->mmap_sem);
===================================================================
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -29,6 +29,7 @@
 #include <asm/uaccess.h>
 #include <asm/cacheflush.h>
 #include <asm/tlb.h>
+#include <asm/mmu_context.h>
 
 #ifndef arch_mmap_check
 #define arch_mmap_check(addr, len, flags)	(0)
@@ -1976,6 +1977,9 @@ void exit_mmap(struct mm_struct *mm)
 	struct vm_area_struct *vma = mm->mmap;
 	unsigned long nr_accounted = 0;
 	unsigned long end;
+
+	/* mm's last user has gone, and its about to be pulled down */
+	arch_exit_mmap(mm);
 
 	lru_add_drain();
 	flush_cache_mm(mm);

-- 

[patch 09/17] rename struct paravirt_patch to paravirt_patch_site for clarity

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-patch-rename-paravirt_patch.patch --]
[-- Type: text/plain, Size: 3349 bytes --]

Rename struct paravirt_patch to paravirt_patch_site, so that it
clearly refers to a callsite, and not the patch which may be applied
to that callsite.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/alternative.c |    9 ++++-----
 arch/i386/kernel/vmi.c         |    4 ----
 include/asm-i386/alternative.h |   12 +++++++-----
 include/asm-i386/paravirt.h    |    5 ++++-
 4 files changed, 15 insertions(+), 15 deletions(-)

===================================================================
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -359,9 +359,10 @@ void alternatives_smp_switch(int smp)
 #endif
 
 #ifdef CONFIG_PARAVIRT
-void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
-{
-	struct paravirt_patch *p;
+void apply_paravirt(struct paravirt_patch_site *start,
+		    struct paravirt_patch_site *end)
+{
+	struct paravirt_patch_site *p;
 
 	for (p = start; p < end; p++) {
 		unsigned int used;
@@ -388,8 +389,6 @@ void apply_paravirt(struct paravirt_patc
 	/* Sync to be conservative, in case we patched following instructions */
 	sync_core();
 }
-extern struct paravirt_patch __start_parainstructions[],
-	__stop_parainstructions[];
 #endif	/* CONFIG_PARAVIRT */
 
 void __init alternative_instructions(void)
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -70,10 +70,6 @@ static struct {
 	void (*set_initial_ap_state)(int, int);
 	void (*halt)(void);
 } vmi_ops;
-
-/* XXX move this to alternative.h */
-extern struct paravirt_patch __start_parainstructions[],
-	__stop_parainstructions[];
 
 /*
  * VMI patching routines.
===================================================================
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -154,13 +154,15 @@ static inline void alternatives_smp_swit
 #define LOCK_PREFIX ""
 #endif
 
-struct paravirt_patch;
+struct paravirt_patch_site;
 #ifdef CONFIG_PARAVIRT
-void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
+void apply_paravirt(struct paravirt_patch_site *start,
+		    struct paravirt_patch_site *end);
 #else
-static inline void
-apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
-{}
+static inline void apply_paravirt(struct paravirt_patch_site *start,
+				  struct paravirt_patch_site *end)
+{
+}
 #define __start_parainstructions NULL
 #define __stop_parainstructions NULL
 #endif
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -502,12 +502,15 @@ void _paravirt_nop(void);
 #define paravirt_nop	((void *)_paravirt_nop)
 
 /* These all sit in the .parainstructions section to tell us what to patch. */
-struct paravirt_patch {
+struct paravirt_patch_site {
 	u8 *instr; 		/* original instructions */
 	u8 instrtype;		/* type of this instruction */
 	u8 len;			/* length of original instruction */
 	u16 clobbers;		/* what registers you may clobber */
 };
+
+extern struct paravirt_patch_site __start_parainstructions[],
+	__stop_parainstructions[];
 
 #define paravirt_alt(insn_string, typenum, clobber)	\
 	"771:\n\t" insn_string "\n" "772:\n"		\

-- 

[patch 09/17] rename struct paravirt_patch to paravirt_patch_site for clarity

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-patch-rename-paravirt_patch.patch --]
[-- Type: text/plain, Size: 3447 bytes --]

Rename struct paravirt_patch to paravirt_patch_site, so that it
clearly refers to a callsite, and not the patch which may be applied
to that callsite.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/alternative.c |    9 ++++-----
 arch/i386/kernel/vmi.c         |    4 ----
 include/asm-i386/alternative.h |   12 +++++++-----
 include/asm-i386/paravirt.h    |    5 ++++-
 4 files changed, 15 insertions(+), 15 deletions(-)

===================================================================
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -359,9 +359,10 @@ void alternatives_smp_switch(int smp)
 #endif
 
 #ifdef CONFIG_PARAVIRT
-void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
-{
-	struct paravirt_patch *p;
+void apply_paravirt(struct paravirt_patch_site *start,
+		    struct paravirt_patch_site *end)
+{
+	struct paravirt_patch_site *p;
 
 	for (p = start; p < end; p++) {
 		unsigned int used;
@@ -388,8 +389,6 @@ void apply_paravirt(struct paravirt_patc
 	/* Sync to be conservative, in case we patched following instructions */
 	sync_core();
 }
-extern struct paravirt_patch __start_parainstructions[],
-	__stop_parainstructions[];
 #endif	/* CONFIG_PARAVIRT */
 
 void __init alternative_instructions(void)
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -70,10 +70,6 @@ static struct {
 	void (*set_initial_ap_state)(int, int);
 	void (*halt)(void);
 } vmi_ops;
-
-/* XXX move this to alternative.h */
-extern struct paravirt_patch __start_parainstructions[],
-	__stop_parainstructions[];
 
 /*
  * VMI patching routines.
===================================================================
--- a/include/asm-i386/alternative.h
+++ b/include/asm-i386/alternative.h
@@ -154,13 +154,15 @@ static inline void alternatives_smp_swit
 #define LOCK_PREFIX ""
 #endif
 
-struct paravirt_patch;
+struct paravirt_patch_site;
 #ifdef CONFIG_PARAVIRT
-void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end);
+void apply_paravirt(struct paravirt_patch_site *start,
+		    struct paravirt_patch_site *end);
 #else
-static inline void
-apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end)
-{}
+static inline void apply_paravirt(struct paravirt_patch_site *start,
+				  struct paravirt_patch_site *end)
+{
+}
 #define __start_parainstructions NULL
 #define __stop_parainstructions NULL
 #endif
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -502,12 +502,15 @@ void _paravirt_nop(void);
 #define paravirt_nop	((void *)_paravirt_nop)
 
 /* These all sit in the .parainstructions section to tell us what to patch. */
-struct paravirt_patch {
+struct paravirt_patch_site {
 	u8 *instr; 		/* original instructions */
 	u8 instrtype;		/* type of this instruction */
 	u8 len;			/* length of original instruction */
 	u16 clobbers;		/* what registers you may clobber */
 };
+
+extern struct paravirt_patch_site __start_parainstructions[],
+	__stop_parainstructions[];
 
 #define paravirt_alt(insn_string, typenum, clobber)	\
 	"771:\n\t" insn_string "\n" "772:\n"		\

-- 

[patch 10/17] Use patch site IDs computed from offset in paravirt_ops structure

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-use-offset-site-ids.patch --]
[-- Type: text/plain, Size: 12561 bytes --]

Use patch type identifiers derived from the offset of the operation in
the paravirt_ops structure.  This avoids having to maintain a separate
enum for patch site types.

Also, since the identifier is derived from the offset into
paravirt_ops, the offset can be derived from the identifier.  This is
used to remove replicated information in the various callsite macros,
which has been a source of bugs in the past.

This patch also drops the fused save_fl+cli operation, which doesn't
really add much and makes things more complex - specifically because
it breaks the 1:1 relationship between identifiers and offsets.  If
this operation turns out to be particularly beneficial, then the right
answer is to define a new entrypoint for it.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/paravirt.c |   14 +--
 arch/i386/kernel/vmi.c      |   39 +--------
 include/asm-i386/paravirt.h |  179 ++++++++++++++++++++++---------------------
 3 files changed, 105 insertions(+), 127 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -58,7 +58,6 @@ DEF_NATIVE(sti, "sti");
 DEF_NATIVE(sti, "sti");
 DEF_NATIVE(popf, "push %eax; popf");
 DEF_NATIVE(pushf, "pushf; pop %eax");
-DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
 DEF_NATIVE(iret, "iret");
 DEF_NATIVE(sti_sysexit, "sti; sysexit");
 
@@ -66,13 +65,12 @@ static const struct native_insns
 {
 	const char *start, *end;
 } native_insns[] = {
-	[PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
-	[PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
-	[PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
-	[PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
-	[PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
-	[PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
-	[PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit },
+	[PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
+	[PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
+	[PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
+	[PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
+	[PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
+	[PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
 };
 
 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -78,11 +78,6 @@ static struct {
 #define MNEM_JMP  0xe9
 #define MNEM_RET  0xc3
 
-static char irq_save_disable_callout[] = {
-	MNEM_CALL, 0, 0, 0, 0,
-	MNEM_CALL, 0, 0, 0, 0,
-	MNEM_RET
-};
 #define IRQ_PATCH_INT_MASK 0
 #define IRQ_PATCH_DISABLE  5
 
@@ -130,33 +125,17 @@ static unsigned vmi_patch(u8 type, u16 c
 static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len)
 {
 	switch (type) {
-		case PARAVIRT_IRQ_DISABLE:
+		case PARAVIRT_PATCH(irq_disable):
 			return patch_internal(VMI_CALL_DisableInterrupts, len, insns);
-		case PARAVIRT_IRQ_ENABLE:
+		case PARAVIRT_PATCH(irq_enable):
 			return patch_internal(VMI_CALL_EnableInterrupts, len, insns);
-		case PARAVIRT_RESTORE_FLAGS:
+		case PARAVIRT_PATCH(restore_fl):
 			return patch_internal(VMI_CALL_SetInterruptMask, len, insns);
-		case PARAVIRT_SAVE_FLAGS:
+		case PARAVIRT_PATCH(save_fl):
 			return patch_internal(VMI_CALL_GetInterruptMask, len, insns);
-        	case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE:
-			if (len >= 10) {
-				patch_internal(VMI_CALL_GetInterruptMask, len, insns);
-				patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5);
-				return 10;
-			} else {
-				/*
-				 * You bastards didn't leave enough room to
-				 * patch save_flags_irq_disable inline.  Patch
-				 * to a helper
-				 */
-				BUG_ON(len < 5);
-				*(char *)insns = MNEM_CALL;
-				patch_offset(insns, irq_save_disable_callout);
-				return 5;
-			}
-		case PARAVIRT_INTERRUPT_RETURN:
+		case PARAVIRT_PATCH(iret):
 			return patch_internal(VMI_CALL_IRET, len, insns);
-		case PARAVIRT_STI_SYSEXIT:
+		case PARAVIRT_PATCH(irq_enable_sysexit):
 			return patch_internal(VMI_CALL_SYSEXIT, len, insns);
 		default:
 			break;
@@ -763,12 +742,6 @@ static inline int __init activate_vmi(vo
 	para_fill(restore_fl, SetInterruptMask);
 	para_fill(irq_disable, DisableInterrupts);
 	para_fill(irq_enable, EnableInterrupts);
-
-	/* irq_save_disable !!! sheer pain */
-	patch_offset(&irq_save_disable_callout[IRQ_PATCH_INT_MASK],
-		     (char *)paravirt_ops.save_fl);
-	patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE],
-		     (char *)paravirt_ops.irq_disable);
 
 	para_fill(wbinvd, WBINVD);
 	para_fill(read_tsc, RDTSC);
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -4,18 +4,7 @@
  * para-virtualization: those hooks are defined here. */
 
 #ifdef CONFIG_PARAVIRT
-#include <linux/stringify.h>
 #include <asm/page.h>
-
-/* These are the most performance critical ops, so we want to be able to patch
- * callers */
-#define PARAVIRT_IRQ_DISABLE 0
-#define PARAVIRT_IRQ_ENABLE 1
-#define PARAVIRT_RESTORE_FLAGS 2
-#define PARAVIRT_SAVE_FLAGS 3
-#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
-#define PARAVIRT_INTERRUPT_RETURN 5
-#define PARAVIRT_STI_SYSEXIT 6
 
 /* Bitmask of what can be clobbered: usually at least eax. */
 #define CLBR_NONE 0x0
@@ -191,6 +180,28 @@ struct paravirt_ops
 
 extern struct paravirt_ops paravirt_ops;
 
+#define PARAVIRT_PATCH(x)					\
+	(offsetof(struct paravirt_ops, x) / sizeof(void *))
+
+#define paravirt_type(type)					\
+	[paravirt_typenum] "i" (PARAVIRT_PATCH(type))
+#define paravirt_clobber(clobber)		\
+	[paravirt_clobber] "i" (clobber)
+
+#define PARAVIRT_CALL	"call *paravirt_ops+%c[paravirt_typenum]*4;"
+
+#define _paravirt_alt(insn_string, type, clobber)	\
+	"771:\n\t" insn_string "\n" "772:\n"		\
+	".pushsection .parainstructions,\"a\"\n"	\
+	"  .long 771b\n"				\
+	"  .byte " type "\n"				\
+	"  .byte 772b-771b\n"				\
+	"  .short " clobber "\n"			\
+	".popsection\n"
+
+#define paravirt_alt(insn_string)				\
+	_paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")
+
 #define paravirt_enabled() (paravirt_ops.paravirt_enabled)
 
 static inline void load_esp0(struct tss_struct *tss,
@@ -512,93 +523,89 @@ extern struct paravirt_patch_site __star
 extern struct paravirt_patch_site __start_parainstructions[],
 	__stop_parainstructions[];
 
-#define paravirt_alt(insn_string, typenum, clobber)	\
-	"771:\n\t" insn_string "\n" "772:\n"		\
-	".pushsection .parainstructions,\"a\"\n"	\
-	"  .long 771b\n"				\
-	"  .byte " __stringify(typenum) "\n"		\
-	"  .byte 772b-771b\n"				\
-	"  .short " __stringify(clobber) "\n"		\
-	".popsection"
-
 static inline unsigned long __raw_local_save_flags(void)
 {
 	unsigned long f;
 
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_SAVE_FLAGS, CLBR_NONE)
-			     : "=a"(f): "m"(paravirt_ops.save_fl)
-			     : "memory", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     : "=a"(f)
+		     : paravirt_type(save_fl),
+		       paravirt_clobber(CLBR_NONE)
+		     : "memory", "cc");
 	return f;
 }
 
 static inline void raw_local_irq_restore(unsigned long f)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
-			     : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
-			     : "memory", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     : "=a"(f)
+		     : "0"(f),
+		       paravirt_type(restore_fl),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "cc");
 }
 
 static inline void raw_local_irq_disable(void)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%0;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_IRQ_DISABLE, CLBR_EAX)
-			     : : "m" (paravirt_ops.irq_disable)
-			     : "memory", "eax", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     :
+		     : paravirt_type(irq_disable),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "eax", "cc");
 }
 
 static inline void raw_local_irq_enable(void)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%0;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_IRQ_ENABLE, CLBR_EAX)
-			     : : "m" (paravirt_ops.irq_enable)
-			     : "memory", "eax", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     :
+		     : paravirt_type(irq_enable),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "eax", "cc");
 }
 
 static inline unsigned long __raw_local_irq_save(void)
 {
 	unsigned long f;
 
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1; pushl %%eax;"
-					   "call *%2; popl %%eax;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
-					  CLBR_NONE)
-			     : "=a"(f)
-			     : "m" (paravirt_ops.save_fl),
-			       "m" (paravirt_ops.irq_disable)
-			     : "memory", "cc");
+	f = __raw_local_save_flags();
+	raw_local_irq_disable();
 	return f;
 }
 
-#define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"		\
-		     "call *paravirt_ops+%c[irq_disable];"		\
-		     "popl %%edx; popl %%ecx",				\
-		     PARAVIRT_IRQ_DISABLE, CLBR_EAX)
-
-#define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"		\
-		     "call *paravirt_ops+%c[irq_enable];"		\
-		     "popl %%edx; popl %%ecx",				\
-		     PARAVIRT_IRQ_ENABLE, CLBR_EAX)
+#define CLI_STRING							\
+	_paravirt_alt("pushl %%ecx; pushl %%edx;"			\
+		      "call *paravirt_ops+%c[paravirt_cli_type]*4;"	\
+		      "popl %%edx; popl %%ecx",				\
+		      "%c[paravirt_cli_type]", "%c[paravirt_clobber]")
+
+#define STI_STRING							\
+	_paravirt_alt("pushl %%ecx; pushl %%edx;"			\
+		      "call *paravirt_ops+%c[paravirt_sti_type]*4;"	\
+		      "popl %%edx; popl %%ecx",				\
+		      "%c[paravirt_sti_type]", "%c[paravirt_clobber]")
+
 #define CLI_STI_CLOBBERS , "%eax"
-#define CLI_STI_INPUT_ARGS \
+#define CLI_STI_INPUT_ARGS						\
 	,								\
-	[irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)),	\
-	[irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
+	[paravirt_cli_type] "i" (PARAVIRT_PATCH(irq_disable)),		\
+	[paravirt_sti_type] "i" (PARAVIRT_PATCH(irq_enable)),		\
+	paravirt_clobber(CLBR_EAX)
+
+#undef PARAVIRT_CALL
 
 #else  /* __ASSEMBLY__ */
 
-#define PARA_PATCH(ptype, clobbers, ops)	\
+#define PARA_PATCH(off)	((off) / 4)
+
+#define PARA_SITE(ptype, clobbers, ops)		\
 771:;						\
 	ops;					\
 772:;						\
@@ -609,25 +616,25 @@ 772:;						\
 	 .short clobbers;			\
 	.popsection
 
-#define INTERRUPT_RETURN				\
-	PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY,	\
-	jmp *%cs:paravirt_ops+PARAVIRT_iret)
-
-#define DISABLE_INTERRUPTS(clobbers)			\
-	PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers,	\
-	pushl %ecx; pushl %edx;				\
-	call *paravirt_ops+PARAVIRT_irq_disable;	\
-	popl %edx; popl %ecx)				\
-
-#define ENABLE_INTERRUPTS(clobbers)			\
-	PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers,	\
-	pushl %ecx; pushl %edx;				\
-	call *%cs:paravirt_ops+PARAVIRT_irq_enable;	\
-	popl %edx; popl %ecx)
-
-#define ENABLE_INTERRUPTS_SYSEXIT			\
-	PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY,	\
-	jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
+#define INTERRUPT_RETURN					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_iret), CLBR_ANY,		\
+		  jmp *%cs:paravirt_ops+PARAVIRT_iret)
+
+#define DISABLE_INTERRUPTS(clobbers)					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers,		\
+		  pushl %ecx; pushl %edx;				\
+		  call *%cs:paravirt_ops+PARAVIRT_irq_disable;		\
+		  popl %edx; popl %ecx)					\
+
+#define ENABLE_INTERRUPTS(clobbers)					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers,		\
+		  pushl %ecx; pushl %edx;				\
+		  call *%cs:paravirt_ops+PARAVIRT_irq_enable;		\
+		  popl %edx; popl %ecx)
+
+#define ENABLE_INTERRUPTS_SYSEXIT					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY,	\
+		  jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 
 #define GET_CR0_INTO_EAX			\
 	call *paravirt_ops+PARAVIRT_read_cr0

-- 

[patch 10/17] Use patch site IDs computed from offset in paravirt_ops structure

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-use-offset-site-ids.patch --]
[-- Type: text/plain, Size: 12926 bytes --]

Use patch type identifiers derived from the offset of the operation in
the paravirt_ops structure.  This avoids having to maintain a separate
enum for patch site types.

Also, since the identifier is derived from the offset into
paravirt_ops, the offset can be derived from the identifier.  This is
used to remove replicated information in the various callsite macros,
which has been a source of bugs in the past.

This patch also drops the fused save_fl+cli operation, which doesn't
really add much and makes things more complex - specifically because
it breaks the 1:1 relationship between identifiers and offsets.  If
this operation turns out to be particularly beneficial, then the right
answer is to define a new entrypoint for it.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/paravirt.c |   14 +--
 arch/i386/kernel/vmi.c      |   39 +--------
 include/asm-i386/paravirt.h |  179 ++++++++++++++++++++++---------------------
 3 files changed, 105 insertions(+), 127 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -58,7 +58,6 @@ DEF_NATIVE(sti, "sti");
 DEF_NATIVE(sti, "sti");
 DEF_NATIVE(popf, "push %eax; popf");
 DEF_NATIVE(pushf, "pushf; pop %eax");
-DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
 DEF_NATIVE(iret, "iret");
 DEF_NATIVE(sti_sysexit, "sti; sysexit");
 
@@ -66,13 +65,12 @@ static const struct native_insns
 {
 	const char *start, *end;
 } native_insns[] = {
-	[PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli },
-	[PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti },
-	[PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf },
-	[PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf },
-	[PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli },
-	[PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret },
-	[PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit },
+	[PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
+	[PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
+	[PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
+	[PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
+	[PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
+	[PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
 };
 
 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -78,11 +78,6 @@ static struct {
 #define MNEM_JMP  0xe9
 #define MNEM_RET  0xc3
 
-static char irq_save_disable_callout[] = {
-	MNEM_CALL, 0, 0, 0, 0,
-	MNEM_CALL, 0, 0, 0, 0,
-	MNEM_RET
-};
 #define IRQ_PATCH_INT_MASK 0
 #define IRQ_PATCH_DISABLE  5
 
@@ -130,33 +125,17 @@ static unsigned vmi_patch(u8 type, u16 c
 static unsigned vmi_patch(u8 type, u16 clobbers, void *insns, unsigned len)
 {
 	switch (type) {
-		case PARAVIRT_IRQ_DISABLE:
+		case PARAVIRT_PATCH(irq_disable):
 			return patch_internal(VMI_CALL_DisableInterrupts, len, insns);
-		case PARAVIRT_IRQ_ENABLE:
+		case PARAVIRT_PATCH(irq_enable):
 			return patch_internal(VMI_CALL_EnableInterrupts, len, insns);
-		case PARAVIRT_RESTORE_FLAGS:
+		case PARAVIRT_PATCH(restore_fl):
 			return patch_internal(VMI_CALL_SetInterruptMask, len, insns);
-		case PARAVIRT_SAVE_FLAGS:
+		case PARAVIRT_PATCH(save_fl):
 			return patch_internal(VMI_CALL_GetInterruptMask, len, insns);
-        	case PARAVIRT_SAVE_FLAGS_IRQ_DISABLE:
-			if (len >= 10) {
-				patch_internal(VMI_CALL_GetInterruptMask, len, insns);
-				patch_internal(VMI_CALL_DisableInterrupts, len-5, insns+5);
-				return 10;
-			} else {
-				/*
-				 * You bastards didn't leave enough room to
-				 * patch save_flags_irq_disable inline.  Patch
-				 * to a helper
-				 */
-				BUG_ON(len < 5);
-				*(char *)insns = MNEM_CALL;
-				patch_offset(insns, irq_save_disable_callout);
-				return 5;
-			}
-		case PARAVIRT_INTERRUPT_RETURN:
+		case PARAVIRT_PATCH(iret):
 			return patch_internal(VMI_CALL_IRET, len, insns);
-		case PARAVIRT_STI_SYSEXIT:
+		case PARAVIRT_PATCH(irq_enable_sysexit):
 			return patch_internal(VMI_CALL_SYSEXIT, len, insns);
 		default:
 			break;
@@ -763,12 +742,6 @@ static inline int __init activate_vmi(vo
 	para_fill(restore_fl, SetInterruptMask);
 	para_fill(irq_disable, DisableInterrupts);
 	para_fill(irq_enable, EnableInterrupts);
-
-	/* irq_save_disable !!! sheer pain */
-	patch_offset(&irq_save_disable_callout[IRQ_PATCH_INT_MASK],
-		     (char *)paravirt_ops.save_fl);
-	patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE],
-		     (char *)paravirt_ops.irq_disable);
 
 	para_fill(wbinvd, WBINVD);
 	para_fill(read_tsc, RDTSC);
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -4,18 +4,7 @@
  * para-virtualization: those hooks are defined here. */
 
 #ifdef CONFIG_PARAVIRT
-#include <linux/stringify.h>
 #include <asm/page.h>
-
-/* These are the most performance critical ops, so we want to be able to patch
- * callers */
-#define PARAVIRT_IRQ_DISABLE 0
-#define PARAVIRT_IRQ_ENABLE 1
-#define PARAVIRT_RESTORE_FLAGS 2
-#define PARAVIRT_SAVE_FLAGS 3
-#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4
-#define PARAVIRT_INTERRUPT_RETURN 5
-#define PARAVIRT_STI_SYSEXIT 6
 
 /* Bitmask of what can be clobbered: usually at least eax. */
 #define CLBR_NONE 0x0
@@ -191,6 +180,28 @@ struct paravirt_ops
 
 extern struct paravirt_ops paravirt_ops;
 
+#define PARAVIRT_PATCH(x)					\
+	(offsetof(struct paravirt_ops, x) / sizeof(void *))
+
+#define paravirt_type(type)					\
+	[paravirt_typenum] "i" (PARAVIRT_PATCH(type))
+#define paravirt_clobber(clobber)		\
+	[paravirt_clobber] "i" (clobber)
+
+#define PARAVIRT_CALL	"call *paravirt_ops+%c[paravirt_typenum]*4;"
+
+#define _paravirt_alt(insn_string, type, clobber)	\
+	"771:\n\t" insn_string "\n" "772:\n"		\
+	".pushsection .parainstructions,\"a\"\n"	\
+	"  .long 771b\n"				\
+	"  .byte " type "\n"				\
+	"  .byte 772b-771b\n"				\
+	"  .short " clobber "\n"			\
+	".popsection\n"
+
+#define paravirt_alt(insn_string)				\
+	_paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")
+
 #define paravirt_enabled() (paravirt_ops.paravirt_enabled)
 
 static inline void load_esp0(struct tss_struct *tss,
@@ -512,93 +523,89 @@ extern struct paravirt_patch_site __star
 extern struct paravirt_patch_site __start_parainstructions[],
 	__stop_parainstructions[];
 
-#define paravirt_alt(insn_string, typenum, clobber)	\
-	"771:\n\t" insn_string "\n" "772:\n"		\
-	".pushsection .parainstructions,\"a\"\n"	\
-	"  .long 771b\n"				\
-	"  .byte " __stringify(typenum) "\n"		\
-	"  .byte 772b-771b\n"				\
-	"  .short " __stringify(clobber) "\n"		\
-	".popsection"
-
 static inline unsigned long __raw_local_save_flags(void)
 {
 	unsigned long f;
 
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_SAVE_FLAGS, CLBR_NONE)
-			     : "=a"(f): "m"(paravirt_ops.save_fl)
-			     : "memory", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     : "=a"(f)
+		     : paravirt_type(save_fl),
+		       paravirt_clobber(CLBR_NONE)
+		     : "memory", "cc");
 	return f;
 }
 
 static inline void raw_local_irq_restore(unsigned long f)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_RESTORE_FLAGS, CLBR_EAX)
-			     : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f)
-			     : "memory", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     : "=a"(f)
+		     : "0"(f),
+		       paravirt_type(restore_fl),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "cc");
 }
 
 static inline void raw_local_irq_disable(void)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%0;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_IRQ_DISABLE, CLBR_EAX)
-			     : : "m" (paravirt_ops.irq_disable)
-			     : "memory", "eax", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     :
+		     : paravirt_type(irq_disable),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "eax", "cc");
 }
 
 static inline void raw_local_irq_enable(void)
 {
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%0;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_IRQ_ENABLE, CLBR_EAX)
-			     : : "m" (paravirt_ops.irq_enable)
-			     : "memory", "eax", "cc");
+	asm volatile(paravirt_alt("pushl %%ecx; pushl %%edx;"
+				  PARAVIRT_CALL
+				  "popl %%edx; popl %%ecx")
+		     :
+		     : paravirt_type(irq_enable),
+		       paravirt_clobber(CLBR_EAX)
+		     : "memory", "eax", "cc");
 }
 
 static inline unsigned long __raw_local_irq_save(void)
 {
 	unsigned long f;
 
-	__asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;"
-					   "call *%1; pushl %%eax;"
-					   "call *%2; popl %%eax;"
-					   "popl %%edx; popl %%ecx",
-					  PARAVIRT_SAVE_FLAGS_IRQ_DISABLE,
-					  CLBR_NONE)
-			     : "=a"(f)
-			     : "m" (paravirt_ops.save_fl),
-			       "m" (paravirt_ops.irq_disable)
-			     : "memory", "cc");
+	f = __raw_local_save_flags();
+	raw_local_irq_disable();
 	return f;
 }
 
-#define CLI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"		\
-		     "call *paravirt_ops+%c[irq_disable];"		\
-		     "popl %%edx; popl %%ecx",				\
-		     PARAVIRT_IRQ_DISABLE, CLBR_EAX)
-
-#define STI_STRING paravirt_alt("pushl %%ecx; pushl %%edx;"		\
-		     "call *paravirt_ops+%c[irq_enable];"		\
-		     "popl %%edx; popl %%ecx",				\
-		     PARAVIRT_IRQ_ENABLE, CLBR_EAX)
+#define CLI_STRING							\
+	_paravirt_alt("pushl %%ecx; pushl %%edx;"			\
+		      "call *paravirt_ops+%c[paravirt_cli_type]*4;"	\
+		      "popl %%edx; popl %%ecx",				\
+		      "%c[paravirt_cli_type]", "%c[paravirt_clobber]")
+
+#define STI_STRING							\
+	_paravirt_alt("pushl %%ecx; pushl %%edx;"			\
+		      "call *paravirt_ops+%c[paravirt_sti_type]*4;"	\
+		      "popl %%edx; popl %%ecx",				\
+		      "%c[paravirt_sti_type]", "%c[paravirt_clobber]")
+
 #define CLI_STI_CLOBBERS , "%eax"
-#define CLI_STI_INPUT_ARGS \
+#define CLI_STI_INPUT_ARGS						\
 	,								\
-	[irq_disable] "i" (offsetof(struct paravirt_ops, irq_disable)),	\
-	[irq_enable] "i" (offsetof(struct paravirt_ops, irq_enable))
+	[paravirt_cli_type] "i" (PARAVIRT_PATCH(irq_disable)),		\
+	[paravirt_sti_type] "i" (PARAVIRT_PATCH(irq_enable)),		\
+	paravirt_clobber(CLBR_EAX)
+
+#undef PARAVIRT_CALL
 
 #else  /* __ASSEMBLY__ */
 
-#define PARA_PATCH(ptype, clobbers, ops)	\
+#define PARA_PATCH(off)	((off) / 4)
+
+#define PARA_SITE(ptype, clobbers, ops)		\
 771:;						\
 	ops;					\
 772:;						\
@@ -609,25 +616,25 @@ 772:;						\
 	 .short clobbers;			\
 	.popsection
 
-#define INTERRUPT_RETURN				\
-	PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY,	\
-	jmp *%cs:paravirt_ops+PARAVIRT_iret)
-
-#define DISABLE_INTERRUPTS(clobbers)			\
-	PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers,	\
-	pushl %ecx; pushl %edx;				\
-	call *paravirt_ops+PARAVIRT_irq_disable;	\
-	popl %edx; popl %ecx)				\
-
-#define ENABLE_INTERRUPTS(clobbers)			\
-	PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers,	\
-	pushl %ecx; pushl %edx;				\
-	call *%cs:paravirt_ops+PARAVIRT_irq_enable;	\
-	popl %edx; popl %ecx)
-
-#define ENABLE_INTERRUPTS_SYSEXIT			\
-	PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY,	\
-	jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
+#define INTERRUPT_RETURN					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_iret), CLBR_ANY,		\
+		  jmp *%cs:paravirt_ops+PARAVIRT_iret)
+
+#define DISABLE_INTERRUPTS(clobbers)					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers,		\
+		  pushl %ecx; pushl %edx;				\
+		  call *%cs:paravirt_ops+PARAVIRT_irq_disable;		\
+		  popl %edx; popl %ecx)					\
+
+#define ENABLE_INTERRUPTS(clobbers)					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers,		\
+		  pushl %ecx; pushl %edx;				\
+		  call *%cs:paravirt_ops+PARAVIRT_irq_enable;		\
+		  popl %edx; popl %ecx)
+
+#define ENABLE_INTERRUPTS_SYSEXIT					\
+	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY,	\
+		  jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit)
 
 #define GET_CR0_INTO_EAX			\
 	call *paravirt_ops+PARAVIRT_read_cr0

-- 

[patch 11/17] Fix patch site clobbers to include return register

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-fix-clobbers.patch --]
[-- Type: text/plain, Size: 2038 bytes --]

Fix a few clobbers to include the return register.  The clobbers set
is the set of all registers modified (or may be modified) by the code
snippet, regardless of whether it was deliberate or accidental.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/entry.S    |    2 +-
 include/asm-i386/paravirt.h |   10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

===================================================================
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -342,7 +342,7 @@ 1:	movl (%ebp),%ebp
 	jae syscall_badsys
 	call *sys_call_table(,%eax,4)
 	movl %eax,PT_EAX(%esp)
-	DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
+	DISABLE_INTERRUPTS(CLBR_ANY)
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testw $_TIF_ALLWORK_MASK, %cx
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -532,7 +532,7 @@ static inline unsigned long __raw_local_
 				  "popl %%edx; popl %%ecx")
 		     : "=a"(f)
 		     : paravirt_type(save_fl),
-		       paravirt_clobber(CLBR_NONE)
+		       paravirt_clobber(CLBR_EAX)
 		     : "memory", "cc");
 	return f;
 }
@@ -622,15 +622,15 @@ 772:;						\
 
 #define DISABLE_INTERRUPTS(clobbers)					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers,		\
-		  pushl %ecx; pushl %edx;				\
+		  pushl %eax; pushl %ecx; pushl %edx;			\
 		  call *%cs:paravirt_ops+PARAVIRT_irq_disable;		\
-		  popl %edx; popl %ecx)					\
+		  popl %edx; popl %ecx; popl %eax)			\
 
 #define ENABLE_INTERRUPTS(clobbers)					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers,		\
-		  pushl %ecx; pushl %edx;				\
+		  pushl %eax; pushl %ecx; pushl %edx;			\
 		  call *%cs:paravirt_ops+PARAVIRT_irq_enable;		\
-		  popl %edx; popl %ecx)
+		  popl %edx; popl %ecx; popl %eax)
 
 #define ENABLE_INTERRUPTS_SYSEXIT					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY,	\

-- 

[patch 11/17] Fix patch site clobbers to include return register

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-fix-clobbers.patch --]
[-- Type: text/plain, Size: 2094 bytes --]

Fix a few clobbers to include the return register.  The clobbers set
is the set of all registers modified (or may be modified) by the code
snippet, regardless of whether it was deliberate or accidental.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/entry.S    |    2 +-
 include/asm-i386/paravirt.h |   10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

===================================================================
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -342,7 +342,7 @@ 1:	movl (%ebp),%ebp
 	jae syscall_badsys
 	call *sys_call_table(,%eax,4)
 	movl %eax,PT_EAX(%esp)
-	DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX)
+	DISABLE_INTERRUPTS(CLBR_ANY)
 	TRACE_IRQS_OFF
 	movl TI_flags(%ebp), %ecx
 	testw $_TIF_ALLWORK_MASK, %cx
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -532,7 +532,7 @@ static inline unsigned long __raw_local_
 				  "popl %%edx; popl %%ecx")
 		     : "=a"(f)
 		     : paravirt_type(save_fl),
-		       paravirt_clobber(CLBR_NONE)
+		       paravirt_clobber(CLBR_EAX)
 		     : "memory", "cc");
 	return f;
 }
@@ -622,15 +622,15 @@ 772:;						\
 
 #define DISABLE_INTERRUPTS(clobbers)					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_disable), clobbers,		\
-		  pushl %ecx; pushl %edx;				\
+		  pushl %eax; pushl %ecx; pushl %edx;			\
 		  call *%cs:paravirt_ops+PARAVIRT_irq_disable;		\
-		  popl %edx; popl %ecx)					\
+		  popl %edx; popl %ecx; popl %eax)			\
 
 #define ENABLE_INTERRUPTS(clobbers)					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable), clobbers,		\
-		  pushl %ecx; pushl %edx;				\
+		  pushl %eax; pushl %ecx; pushl %edx;			\
 		  call *%cs:paravirt_ops+PARAVIRT_irq_enable;		\
-		  popl %edx; popl %ecx)
+		  popl %edx; popl %ecx; popl %eax)
 
 #define ENABLE_INTERRUPTS_SYSEXIT					\
 	PARA_SITE(PARA_PATCH(PARAVIRT_irq_enable_sysexit), CLBR_ANY,	\

-- 

[patch 12/17] Consistently wrap paravirt ops callsites to make them patchable

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-patchable-call-wrappers.patch --]
[-- Type: text/plain, Size: 26453 bytes --]

Wrap a set of interesting paravirt_ops calls in a wrapper which makes
the callsites available for patching.  Unfortunately this is pretty
ugly because there's no way to get gcc to generate a function call,
but also wrap just the callsite itself with the necessary labels.

This patch supports functions with 0-4 arguments, and either void or
returning a value.  64-bit arguments must be split into a pair of
32-bit arguments (lower word first).  Small structures are returned in
registers.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>

---
 include/asm-i386/paravirt.h |  715 ++++++++++++++++++++++++++++++++++---------
 1 file changed, 569 insertions(+), 146 deletions(-)

===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -124,7 +124,7 @@ struct paravirt_ops
 
 	void (*flush_tlb_user)(void);
 	void (*flush_tlb_kernel)(void);
-	void (*flush_tlb_single)(u32 addr);
+	void (*flush_tlb_single)(unsigned long addr);
 
 	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
@@ -188,7 +188,7 @@ extern struct paravirt_ops paravirt_ops;
 #define paravirt_clobber(clobber)		\
 	[paravirt_clobber] "i" (clobber)
 
-#define PARAVIRT_CALL	"call *paravirt_ops+%c[paravirt_typenum]*4;"
+#define PARAVIRT_CALL	"call *(paravirt_ops+%c[paravirt_typenum]*4);"
 
 #define _paravirt_alt(insn_string, type, clobber)	\
 	"771:\n\t" insn_string "\n" "772:\n"		\
@@ -199,26 +199,234 @@ extern struct paravirt_ops paravirt_ops;
 	"  .short " clobber "\n"			\
 	".popsection\n"
 
-#define paravirt_alt(insn_string)				\
+#define paravirt_alt(insn_string)					\
 	_paravirt_alt(insn_string, "%c[paravirt_typenum]", "%c[paravirt_clobber]")
 
-#define paravirt_enabled() (paravirt_ops.paravirt_enabled)
+#define PVOP_CALL0(__rettype, __op)					\
+	({								\
+		__rettype __ret;					\
+		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
+			unsigned long long __tmp;			\
+			unsigned long __ecx;				\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=A" (__tmp), "=c" (__ecx)	\
+				     : paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		} else {						\
+			unsigned long __tmp, __edx, __ecx;		\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=a" (__tmp), "=d" (__edx),	\
+				       "=c" (__ecx)			\
+				     : paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		}							\
+		__ret;							\
+	})
+#define PVOP_VCALL0(__op)						\
+	({								\
+		unsigned long __eax, __edx, __ecx;			\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
+			     : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \
+			     : paravirt_type(__op),			\
+			       paravirt_clobber(CLBR_ANY)		\
+			     : "memory", "cc");				\
+	})
+
+#define PVOP_CALL1(__rettype, __op, arg1)				\
+	({								\
+		__rettype __ret;					\
+		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
+			unsigned long long __tmp;			\
+			unsigned long __ecx;				\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=A" (__tmp), "=c" (__ecx)	\
+				     : "a" ((u32)(arg1)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		} else {						\
+			unsigned long __tmp, __edx, __ecx;		\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=a" (__tmp), "=d" (__edx),	\
+				       "=c" (__ecx)			\
+				     : "0" ((u32)(arg1)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		}							\
+		__ret;							\
+	})
+#define PVOP_VCALL1(__op, arg1)						\
+	({								\
+		unsigned long __eax, __edx, __ecx;			\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
+			     : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \
+			     : "0" ((u32)(arg1)),			\
+			       paravirt_type(__op),			\
+			       paravirt_clobber(CLBR_ANY)		\
+			     : "memory", "cc");				\
+	})
+
+#define PVOP_CALL2(__rettype, __op, arg1, arg2)				\
+	({								\
+		__rettype __ret;					\
+		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
+			unsigned long long __tmp;			\
+			unsigned long __ecx;				\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=A" (__tmp), "=c" (__ecx)	\
+				     : "a" ((u32)(arg1)),		\
+				       "d" ((u32)(arg2)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		} else {						\
+			unsigned long __tmp, __edx, __ecx;		\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=a" (__tmp), "=d" (__edx),	\
+				       "=c" (__ecx)			\
+				     : "0" ((u32)(arg1)),		\
+				       "1" ((u32)(arg2)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		}							\
+		__ret;							\
+	})
+#define PVOP_VCALL2(__op, arg1, arg2)					\
+	({								\
+		unsigned long __eax, __edx, __ecx;			\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
+			     : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \
+			     : "0" ((u32)(arg1)),			\
+			       "1" ((u32)(arg2)),			\
+			       paravirt_type(__op),			\
+			       paravirt_clobber(CLBR_ANY)		\
+			     : "memory", "cc");				\
+	})
+
+#define PVOP_CALL3(__rettype, __op, arg1, arg2, arg3)			\
+	({								\
+		__rettype __ret;					\
+		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
+			unsigned long long __tmp;			\
+			unsigned long __ecx;				\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=A" (__tmp), "=c" (__ecx)	\
+				     : "a" ((u32)(arg1)),		\
+				       "d" ((u32)(arg2)),		\
+				       "1" ((u32)(arg3)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		} else {						\
+			unsigned long __tmp, __edx, __ecx;	\
+			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
+				     : "=a" (__tmp), "=d" (__edx),	\
+				       "=c" (__ecx)			\
+				     : "0" ((u32)(arg1)),		\
+				       "1" ((u32)(arg2)),		\
+				       "2" ((u32)(arg3)),		\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		}							\
+		__ret;							\
+	})
+#define PVOP_VCALL3(__op, arg1, arg2, arg3)				\
+	({								\
+		unsigned long __eax, __edx, __ecx;			\
+		asm volatile(paravirt_alt(PARAVIRT_CALL)		\
+			     : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \
+			     : "0" ((u32)(arg1)),			\
+			       "1" ((u32)(arg2)),			\
+			       "2" ((u32)(arg3)),			\
+			       paravirt_type(__op),			\
+			       paravirt_clobber(CLBR_ANY)		\
+			     : "memory", "cc");				\
+	})
+
+#define PVOP_CALL4(__rettype, __op, arg1, arg2, arg3, arg4)		\
+	({								\
+		__rettype __ret;					\
+		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
+			unsigned long long __tmp;			\
+			unsigned long __ecx;				\
+			asm volatile("push %[_arg4]; "			\
+				     paravirt_alt(PARAVIRT_CALL)	\
+				     "lea 4(%%esp),%%esp"		\
+				     : "=A" (__tmp), "=c" (__ecx)	\
+				     : "a" ((u32)(arg1)),		\
+				       "d" ((u32)(arg2)),		\
+				       "1" ((u32)(arg3)),		\
+				       [_arg4] "mr" ((u32)(arg4)),	\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc",);		\
+			__ret = (__rettype)__tmp;			\
+		} else {						\
+			unsigned long __tmp, __edx, __ecx;		\
+			asm volatile("push %[_arg4]; "			\
+				     paravirt_alt(PARAVIRT_CALL)	\
+				     "lea 4(%%esp),%%esp"		\
+				     : "=a" (__tmp), "=d" (__edx), "=c" (__ecx) \
+				     : "0" ((u32)(arg1)),		\
+				       "1" ((u32)(arg2)),		\
+				       "2" ((u32)(arg3)),		\
+				       [_arg4]"mr" ((u32)(arg4)),	\
+				       paravirt_type(__op),		\
+				       paravirt_clobber(CLBR_ANY)	\
+				     : "memory", "cc");			\
+			__ret = (__rettype)__tmp;			\
+		}							\
+		__ret;							\
+	})
+#define PVOP_VCALL4(__op, arg1, arg2, arg3, arg4)			\
+	({								\
+		unsigned long __eax, __edx, __ecx;			\
+		asm volatile("push %[_arg4]; "				\
+			     paravirt_alt(PARAVIRT_CALL)		\
+			     "lea 4(%%esp),%%esp"			\
+			     : "=a" (__eax), "=d" (__edx), "=c" (__ecx) \
+			     : "0" ((u32)(arg1)),			\
+			       "1" ((u32)(arg2)),			\
+			       "2" ((u32)(arg3)),			\
+			       [_arg4]"mr" ((u32)(arg4)),		\
+			       paravirt_type(__op),			\
+			       paravirt_clobber(CLBR_ANY)		\
+			     : "memory", "cc");				\
+	})
+
+static inline int paravirt_enabled(void)
+{
+	return paravirt_ops.paravirt_enabled;
+}
 
 static inline void load_esp0(struct tss_struct *tss,
 			     struct thread_struct *thread)
 {
-	paravirt_ops.load_esp0(tss, thread);
+	PVOP_VCALL2(load_esp0, tss, thread);
 }
 
 #define ARCH_SETUP			paravirt_ops.arch_setup();
 static inline unsigned long get_wallclock(void)
 {
-	return paravirt_ops.get_wallclock();
+	return PVOP_CALL0(unsigned long, get_wallclock);
 }
 
 static inline int set_wallclock(unsigned long nowtime)
 {
-	return paravirt_ops.set_wallclock(nowtime);
+	return PVOP_CALL1(int, set_wallclock, nowtime);
 }
 
 static inline void (*choose_time_init(void))(void)
@@ -230,127 +438,208 @@ static inline void __cpuid(unsigned int 
 static inline void __cpuid(unsigned int *eax, unsigned int *ebx,
 			   unsigned int *ecx, unsigned int *edx)
 {
-	paravirt_ops.cpuid(eax, ebx, ecx, edx);
+	PVOP_VCALL4(cpuid, eax, ebx, ecx, edx);
 }
 
 /*
  * These special macros can be used to get or set a debugging register
  */
-#define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg)
-#define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val)
-
-#define clts() paravirt_ops.clts()
-
-#define read_cr0() paravirt_ops.read_cr0()
-#define write_cr0(x) paravirt_ops.write_cr0(x)
-
-#define read_cr2() paravirt_ops.read_cr2()
-#define write_cr2(x) paravirt_ops.write_cr2(x)
-
-#define read_cr3() paravirt_ops.read_cr3()
-#define write_cr3(x) paravirt_ops.write_cr3(x)
-
-#define read_cr4() paravirt_ops.read_cr4()
-#define read_cr4_safe(x) paravirt_ops.read_cr4_safe()
-#define write_cr4(x) paravirt_ops.write_cr4(x)
-
-#define raw_ptep_get_and_clear(xp)	(paravirt_ops.ptep_get_and_clear(xp))
+static inline unsigned long paravirt_get_debugreg(int reg)
+{
+	return PVOP_CALL1(unsigned long, get_debugreg, reg);
+}
+#define get_debugreg(var, reg) var = paravirt_get_debugreg(reg)
+static inline void set_debugreg(unsigned long val, int reg)
+{
+	PVOP_VCALL2(set_debugreg, reg, val);
+}
+
+static inline void clts(void)
+{
+	PVOP_VCALL0(clts);
+}
+
+static inline unsigned long read_cr0(void)
+{
+	return PVOP_CALL0(unsigned long, read_cr0);
+}
+
+static inline void write_cr0(unsigned long x)
+{
+	PVOP_VCALL1(write_cr0, x);
+}
+
+static inline unsigned long read_cr2(void)
+{
+	return PVOP_CALL0(unsigned long, read_cr2);
+}
+
+static inline void write_cr2(unsigned long x)
+{
+	PVOP_VCALL1(write_cr2, x);
+}
+
+static inline unsigned long read_cr3(void)
+{
+	return PVOP_CALL0(unsigned long, read_cr3);
+}
+
+static inline void write_cr3(unsigned long x)
+{
+	PVOP_VCALL1(write_cr3, x);
+}
+
+static inline unsigned long read_cr4(void)
+{
+	return PVOP_CALL0(unsigned long, read_cr4);
+}
+static inline unsigned long read_cr4_safe(void)
+{
+	return PVOP_CALL0(unsigned long, read_cr4_safe);
+}
+
+static inline void write_cr4(unsigned long x)
+{
+	PVOP_VCALL1(write_cr4, x);
+}
 
 static inline void raw_safe_halt(void)
 {
-	paravirt_ops.safe_halt();
+	PVOP_VCALL0(safe_halt);
 }
 
 static inline void halt(void)
 {
-	paravirt_ops.safe_halt();
-}
-#define wbinvd() paravirt_ops.wbinvd()
+	PVOP_VCALL0(safe_halt);
+}
+
+static inline void wbinvd(void)
+{
+	PVOP_VCALL0(wbinvd);
+}
 
 #define get_kernel_rpl()  (paravirt_ops.kernel_rpl)
 
+static inline u64 paravirt_read_msr(unsigned msr, int *err)
+{
+	return PVOP_CALL2(u64, read_msr, msr, err);
+}
+static inline int paravirt_write_msr(unsigned msr, unsigned low, unsigned high)
+{
+	return PVOP_CALL3(int, write_msr, msr, low, high);
+}
+
 /* These should all do BUG_ON(_err), but our headers are too tangled. */
-#define rdmsr(msr,val1,val2) do {				\
-	int _err;						\
-	u64 _l = paravirt_ops.read_msr(msr,&_err);		\
-	val1 = (u32)_l;						\
-	val2 = _l >> 32;					\
+#define rdmsr(msr,val1,val2) do {		\
+	int _err;				\
+	u64 _l = paravirt_read_msr(msr, &_err);	\
+	val1 = (u32)_l;				\
+	val2 = _l >> 32;			\
 } while(0)
 
-#define wrmsr(msr,val1,val2) do {				\
-	u64 _l = ((u64)(val2) << 32) | (val1);			\
-	paravirt_ops.write_msr((msr), _l);			\
+#define wrmsr(msr,val1,val2) do {		\
+	paravirt_write_msr(msr, val1, val2);	\
 } while(0)
 
-#define rdmsrl(msr,val) do {					\
-	int _err;						\
-	val = paravirt_ops.read_msr((msr),&_err);		\
+#define rdmsrl(msr,val) do {			\
+	int _err;				\
+	val = paravirt_read_msr(msr, &_err);	\
 } while(0)
 
-#define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val)))
-#define wrmsr_safe(msr,a,b) ({					\
-	u64 _l = ((u64)(b) << 32) | (a);			\
-	paravirt_ops.write_msr((msr),_l);			\
-})
+#define wrmsrl(msr,val)		((void)paravirt_write_msr(msr, val, 0))
+#define wrmsr_safe(msr,a,b)	paravirt_write_msr(msr, a, b)
 
 /* rdmsr with exception handling */
-#define rdmsr_safe(msr,a,b) ({					\
-	int _err;						\
-	u64 _l = paravirt_ops.read_msr(msr,&_err);		\
-	(*a) = (u32)_l;						\
-	(*b) = _l >> 32;					\
+#define rdmsr_safe(msr,a,b) ({			\
+	int _err;				\
+	u64 _l = paravirt_read_msr(msr, &_err);	\
+	(*a) = (u32)_l;				\
+	(*b) = _l >> 32;			\
 	_err; })
 
-#define rdtsc(low,high) do {					\
-	u64 _l = paravirt_ops.read_tsc();			\
-	low = (u32)_l;						\
-	high = _l >> 32;					\
+
+static inline u64 paravirt_read_tsc(void)
+{
+	return PVOP_CALL0(u64, read_tsc);
+}
+#define rdtsc(low,high) do {			\
+	u64 _l = paravirt_read_tsc();		\
+	low = (u32)_l;				\
+	high = _l >> 32;			\
 } while(0)
 
-#define rdtscl(low) do {					\
-	u64 _l = paravirt_ops.read_tsc();			\
-	low = (int)_l;						\
+#define rdtscl(low) do {			\
+	u64 _l = paravirt_read_tsc();		\
+	low = (int)_l;				\
 } while(0)
 
-#define rdtscll(val) (val = paravirt_ops.read_tsc())
+#define rdtscll(val) (val = paravirt_read_tsc())
 
 #define get_scheduled_cycles(val) (val = paravirt_ops.get_scheduled_cycles())
 #define calculate_cpu_khz() (paravirt_ops.get_cpu_khz())
 
 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
 
-#define rdpmc(counter,low,high) do {				\
-	u64 _l = paravirt_ops.read_pmc();			\
-	low = (u32)_l;						\
-	high = _l >> 32;					\
+static inline unsigned long long paravirt_read_pmc(int counter)
+{
+	return PVOP_CALL1(u64, read_pmc, counter);
+}
+
+#define rdpmc(counter,low,high) do {		\
+	u64 _l = paravirt_read_pmc(counter);	\
+	low = (u32)_l;				\
+	high = _l >> 32;			\
 } while(0)
 
-#define load_TR_desc() (paravirt_ops.load_tr_desc())
-#define load_gdt(dtr) (paravirt_ops.load_gdt(dtr))
-#define load_idt(dtr) (paravirt_ops.load_idt(dtr))
-#define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries)))
-#define store_gdt(dtr) (paravirt_ops.store_gdt(dtr))
-#define store_idt(dtr) (paravirt_ops.store_idt(dtr))
-#define store_tr(tr) ((tr) = paravirt_ops.store_tr())
-#define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu)))
-#define write_ldt_entry(dt, entry, low, high)				\
-	(paravirt_ops.write_ldt_entry((dt), (entry), (low), (high)))
-#define write_gdt_entry(dt, entry, low, high)				\
-	(paravirt_ops.write_gdt_entry((dt), (entry), (low), (high)))
-#define write_idt_entry(dt, entry, low, high)				\
-	(paravirt_ops.write_idt_entry((dt), (entry), (low), (high)))
-#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask))
-
-#define __pte(x)	paravirt_ops.make_pte(x)
-#define __pgd(x)	paravirt_ops.make_pgd(x)
-
-#define pte_val(x)	paravirt_ops.pte_val(x)
-#define pgd_val(x)	paravirt_ops.pgd_val(x)
-
-#ifdef CONFIG_X86_PAE
-#define __pmd(x)	paravirt_ops.make_pmd(x)
-#define pmd_val(x)	paravirt_ops.pmd_val(x)
-#endif
+static inline void load_TR_desc(void)
+{
+	PVOP_VCALL0(load_tr_desc);
+}
+static inline void load_gdt(const struct Xgt_desc_struct *dtr)
+{
+	PVOP_VCALL1(load_gdt, dtr);
+}
+static inline void load_idt(const struct Xgt_desc_struct *dtr)
+{
+	PVOP_VCALL1(load_idt, dtr);
+}
+static inline void set_ldt(const void *addr, unsigned entries)
+{
+	PVOP_VCALL2(set_ldt, addr, entries);
+}
+static inline void store_gdt(struct Xgt_desc_struct *dtr)
+{
+	PVOP_VCALL1(store_gdt, dtr);
+}
+static inline void store_idt(struct Xgt_desc_struct *dtr)
+{
+	PVOP_VCALL1(store_idt, dtr);
+}
+static inline unsigned long paravirt_store_tr(void)
+{
+	return PVOP_CALL0(unsigned long, store_tr);
+}
+#define store_tr(tr)	((tr) = paravirt_store_tr())
+static inline void load_TLS(struct thread_struct *t, unsigned cpu)
+{
+	PVOP_VCALL2(load_tls, t, cpu);
+}
+static inline void write_ldt_entry(void *dt, int entry, u32 low, u32 high)
+{
+	PVOP_VCALL4(write_ldt_entry, dt, entry, low, high);
+}
+static inline void write_gdt_entry(void *dt, int entry, u32 low, u32 high)
+{
+	PVOP_VCALL4(write_gdt_entry, dt, entry, low, high);
+}
+static inline void write_idt_entry(void *dt, int entry, u32 low, u32 high)
+{
+	PVOP_VCALL4(write_idt_entry, dt, entry, low, high);
+}
+static inline void set_iopl_mask(unsigned mask)
+{
+	PVOP_VCALL1(set_iopl_mask, mask);
+}
 
 /* The paravirtualized I/O functions */
 static inline void slow_down_io(void) {
@@ -368,27 +657,27 @@ static inline void slow_down_io(void) {
  */
 static inline void apic_write(unsigned long reg, unsigned long v)
 {
-	paravirt_ops.apic_write(reg,v);
+	PVOP_VCALL2(apic_write, reg, v);
 }
 
 static inline void apic_write_atomic(unsigned long reg, unsigned long v)
 {
-	paravirt_ops.apic_write_atomic(reg,v);
+	PVOP_VCALL2(apic_write_atomic, reg, v);
 }
 
 static inline unsigned long apic_read(unsigned long reg)
 {
-	return paravirt_ops.apic_read(reg);
+	return PVOP_CALL1(unsigned long, apic_read, reg);
 }
 
 static inline void setup_boot_clock(void)
 {
-	paravirt_ops.setup_boot_clock();
+	PVOP_VCALL0(setup_boot_clock);
 }
 
 static inline void setup_secondary_clock(void)
 {
-	paravirt_ops.setup_secondary_clock();
+	PVOP_VCALL0(setup_secondary_clock);
 }
 #endif
 
@@ -408,93 +697,205 @@ static inline void startup_ipi_hook(int 
 static inline void startup_ipi_hook(int phys_apicid, unsigned long start_eip,
 				    unsigned long start_esp)
 {
-	return paravirt_ops.startup_ipi_hook(phys_apicid, start_eip, start_esp);
+	PVOP_VCALL3(startup_ipi_hook, phys_apicid, start_eip, start_esp);
 }
 #endif
 
 static inline void paravirt_activate_mm(struct mm_struct *prev,
 					struct mm_struct *next)
 {
-	paravirt_ops.activate_mm(prev, next);
+	PVOP_VCALL2(activate_mm, prev, next);
 }
 
 static inline void arch_dup_mmap(struct mm_struct *oldmm,
 				 struct mm_struct *mm)
 {
-	paravirt_ops.dup_mmap(oldmm, mm);
+	PVOP_VCALL2(dup_mmap, oldmm, mm);
 }
 
 static inline void arch_exit_mmap(struct mm_struct *mm)
 {
-	paravirt_ops.exit_mmap(mm);
-}
-
-#define __flush_tlb() paravirt_ops.flush_tlb_user()
-#define __flush_tlb_global() paravirt_ops.flush_tlb_kernel()
-#define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr)
-
-#define paravirt_map_pt_hook(type, va, pfn) paravirt_ops.map_pt_hook(type, va, pfn)
-
-#define paravirt_alloc_pt(pfn) paravirt_ops.alloc_pt(pfn)
-#define paravirt_release_pt(pfn) paravirt_ops.release_pt(pfn)
-
-#define paravirt_alloc_pd(pfn) paravirt_ops.alloc_pd(pfn)
-#define paravirt_alloc_pd_clone(pfn, clonepfn, start, count) \
-	paravirt_ops.alloc_pd_clone(pfn, clonepfn, start, count)
-#define paravirt_release_pd(pfn) paravirt_ops.release_pd(pfn)
+	PVOP_VCALL1(exit_mmap, mm);
+}
+
+static inline void __flush_tlb(void)
+{
+	PVOP_VCALL0(flush_tlb_user);
+}
+static inline void __flush_tlb_global(void)
+{
+	PVOP_VCALL0(flush_tlb_kernel);
+}
+static inline void __flush_tlb_single(unsigned long addr)
+{
+	PVOP_VCALL1(flush_tlb_single, addr);
+}
+
+static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
+{
+	PVOP_VCALL3(map_pt_hook, type, va, pfn);
+}
+
+static inline void paravirt_alloc_pt(unsigned pfn)
+{
+	PVOP_VCALL1(alloc_pt, pfn);
+}
+static inline void paravirt_release_pt(unsigned pfn)
+{
+	PVOP_VCALL1(release_pt, pfn);
+}
+
+static inline void paravirt_alloc_pd(unsigned pfn)
+{
+	PVOP_VCALL1(alloc_pd, pfn);
+}
+
+static inline void paravirt_alloc_pd_clone(unsigned pfn, unsigned clonepfn,
+					   unsigned start, unsigned count)
+{
+	PVOP_VCALL4(alloc_pd_clone, pfn, clonepfn, start, count);
+}
+static inline void paravirt_release_pd(unsigned pfn)
+{
+	PVOP_VCALL1(release_pd, pfn);
+}
+
+static inline void pte_update(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep)
+{
+	PVOP_VCALL3(pte_update, mm, addr, ptep);
+}
+
+static inline void pte_update_defer(struct mm_struct *mm, unsigned long addr,
+				    pte_t *ptep)
+{
+	PVOP_VCALL3(pte_update_defer, mm, addr, ptep);
+}
+
+#ifdef CONFIG_X86_PAE
+static inline pte_t __pte(unsigned long long val)
+{
+	unsigned long long ret = PVOP_CALL2(unsigned long long, make_pte,
+					    val, val >> 32);
+	return (pte_t) { ret, ret >> 32 };
+}
+
+static inline pmd_t __pmd(unsigned long long val)
+{
+	return (pmd_t) { PVOP_CALL2(unsigned long long, make_pmd, val, val >> 32) };
+}
+
+static inline pgd_t __pgd(unsigned long long val)
+{
+	return (pgd_t) { PVOP_CALL2(unsigned long long, make_pgd, val, val >> 32) };
+}
+
+static inline unsigned long long pte_val(pte_t x)
+{
+	return PVOP_CALL2(unsigned long long, pte_val, x.pte_low, x.pte_high);
+}
+
+static inline unsigned long long pmd_val(pmd_t x)
+{
+	return PVOP_CALL2(unsigned long long, pmd_val, x.pmd, x.pmd >> 32);
+}
+
+static inline unsigned long long pgd_val(pgd_t x)
+{
+	return PVOP_CALL2(unsigned long long, pgd_val, x.pgd, x.pgd >> 32);
+}
 
 static inline void set_pte(pte_t *ptep, pte_t pteval)
 {
-	paravirt_ops.set_pte(ptep, pteval);
+	PVOP_VCALL3(set_pte, ptep, pteval.pte_low, pteval.pte_high);
 }
 
 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep, pte_t pteval)
 {
+	/* 5 arg words */
 	paravirt_ops.set_pte_at(mm, addr, ptep, pteval);
 }
 
+static inline void set_pte_atomic(pte_t *ptep, pte_t pteval)
+{
+	PVOP_VCALL3(set_pte_atomic, ptep, pteval.pte_low, pteval.pte_high);
+}
+
+static inline void set_pte_present(struct mm_struct *mm, unsigned long addr,
+				   pte_t *ptep, pte_t pte)
+{
+	/* 5 arg words */
+	paravirt_ops.set_pte_present(mm, addr, ptep, pte);
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval)
 {
-	paravirt_ops.set_pmd(pmdp, pmdval);
-}
-
-static inline void pte_update(struct mm_struct *mm, u32 addr, pte_t *ptep)
-{
-	paravirt_ops.pte_update(mm, addr, ptep);
-}
-
-static inline void pte_update_defer(struct mm_struct *mm, u32 addr, pte_t *ptep)
-{
-	paravirt_ops.pte_update_defer(mm, addr, ptep);
-}
-
-#ifdef CONFIG_X86_PAE
-static inline void set_pte_atomic(pte_t *ptep, pte_t pteval)
-{
-	paravirt_ops.set_pte_atomic(ptep, pteval);
-}
-
-static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
-{
-	paravirt_ops.set_pte_present(mm, addr, ptep, pte);
+	PVOP_VCALL3(set_pmd, pmdp, pmdval.pmd, pmdval.pmd >> 32);
 }
 
 static inline void set_pud(pud_t *pudp, pud_t pudval)
 {
-	paravirt_ops.set_pud(pudp, pudval);
+	PVOP_VCALL3(set_pud, pudp, pudval.pgd.pgd, pudval.pgd.pgd >> 32);
 }
 
 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
-	paravirt_ops.pte_clear(mm, addr, ptep);
+	PVOP_VCALL3(pte_clear, mm, addr, ptep);
 }
 
 static inline void pmd_clear(pmd_t *pmdp)
 {
-	paravirt_ops.pmd_clear(pmdp);
-}
-#endif
+	PVOP_VCALL1(pmd_clear, pmdp);
+}
+
+static inline pte_t raw_ptep_get_and_clear(pte_t *p)
+{
+	unsigned long long val = PVOP_CALL1(unsigned long long, ptep_get_and_clear, p);
+	return (pte_t) { val, val >> 32 };
+}
+#else  /* !CONFIG_X86_PAE */
+static inline pte_t __pte(unsigned long val)
+{
+	return (pte_t) { PVOP_CALL1(unsigned long, make_pte, val) };
+}
+
+static inline pgd_t __pgd(unsigned long val)
+{
+	return (pgd_t) { PVOP_CALL1(unsigned long, make_pgd, val) };
+}
+
+static inline unsigned long pte_val(pte_t x)
+{
+	return PVOP_CALL1(unsigned long, pte_val, x.pte_low);
+}
+
+static inline unsigned long pgd_val(pgd_t x)
+{
+	return PVOP_CALL1(unsigned long, pgd_val, x.pgd);
+}
+
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+	PVOP_VCALL2(set_pte, ptep, pteval.pte_low);
+}
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+			      pte_t *ptep, pte_t pteval)
+{
+	PVOP_VCALL4(set_pte_at, mm, addr, ptep, pteval.pte_low);
+}
+
+static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval)
+{
+	PVOP_VCALL2(set_pmd, pmdp, pmdval.pud.pgd.pgd);
+}
+
+static inline pte_t raw_ptep_get_and_clear(pte_t *p)
+{
+	return (pte_t) { PVOP_CALL1(unsigned long, ptep_get_and_clear, p) };
+}
+#endif	/* CONFIG_X86_PAE */
 
 /* Lazy mode for batching updates / context switch */
 #define PARAVIRT_LAZY_NONE 0
@@ -502,12 +903,24 @@ static inline void pmd_clear(pmd_t *pmdp
 #define PARAVIRT_LAZY_CPU  2
 
 #define  __HAVE_ARCH_ENTER_LAZY_CPU_MODE
-#define arch_enter_lazy_cpu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_CPU)
-#define arch_leave_lazy_cpu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)
+static inline void arch_enter_lazy_cpu_mode(void)
+{
+	PVOP_VCALL1(set_lazy_mode, PARAVIRT_LAZY_CPU);
+}
+static inline void arch_leave_lazy_cpu_mode(void)
+{
+	PVOP_VCALL1(set_lazy_mode, PARAVIRT_LAZY_NONE);
+}
 
 #define  __HAVE_ARCH_ENTER_LAZY_MMU_MODE
-#define arch_enter_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_MMU)
-#define arch_leave_lazy_mmu_mode() paravirt_ops.set_lazy_mode(PARAVIRT_LAZY_NONE)
+static inline void arch_enter_lazy_mmu_mode(void)
+{
+	PVOP_VCALL1(set_lazy_mode, PARAVIRT_LAZY_MMU);
+}
+static inline void arch_leave_lazy_mmu_mode(void)
+{
+	PVOP_VCALL1(set_lazy_mode, PARAVIRT_LAZY_NONE);
+}
 
 void _paravirt_nop(void);
 #define paravirt_nop	((void *)_paravirt_nop)
@@ -600,6 +1013,16 @@ static inline unsigned long __raw_local_
 	paravirt_clobber(CLBR_EAX)
 
 #undef PARAVIRT_CALL
+#undef PVOP_VCALL0
+#undef PVOP_CALL0
+#undef PVOP_VCALL1
+#undef PVOP_CALL1
+#undef PVOP_VCALL2
+#undef PVOP_CALL2
+#undef PVOP_VCALL3
+#undef PVOP_CALL3
+#undef PVOP_VCALL4
+#undef PVOP_CALL4
 
 #else  /* __ASSEMBLY__ */
 

-- 

Re: [patch 12/17] Consistently wrap paravirt ops callsites to make them patchable

[Andi Kleen]

On Monday 02 April 2007 07:57, Jeremy Fitzhardinge wrote:
> Wrap a set of interesting paravirt_ops calls in a wrapper which makes
> the callsites available for patching.  Unfortunately this is pretty
> ugly because there's no way to get gcc to generate a function call,
> but also wrap just the callsite itself with the necessary labels.
> 
> This patch supports functions with 0-4 arguments, and either void or
> returning a value.  64-bit arguments must be split into a pair of
> 32-bit arguments (lower word first).  Small structures are returned in
> registers.

Can you please add some comments to the code explaining this a little?
Best would be perhaps a overview document in Documentation too.

> +#define PVOP_CALL0(__rettype, __op)					\

The __s shouldn't be needed for the macro arguments because
there is no shared name space with the caller.

> +	({								\
> +		__rettype __ret;					\
> +		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
> +			unsigned long long __tmp;			\
> +			unsigned long __ecx;				\
> +			asm volatile(paravirt_alt(PARAVIRT_CALL)	\

Not having the volatile would probably generate better code, but it 
seems much safer for now.

> +				     : "=A" (__tmp), "=c" (__ecx)	\
> +				     : paravirt_type(__op),		\
> +				       paravirt_clobber(CLBR_ANY)	\
> +				     : "memory", "cc");			\

And the cc clobber is also not needed

-Andi

Re: [patch 12/17] Consistently wrap paravirt ops callsites to make them patchable

[Andi Kleen]

On Monday 02 April 2007 07:57, Jeremy Fitzhardinge wrote:
> Wrap a set of interesting paravirt_ops calls in a wrapper which makes
> the callsites available for patching.  Unfortunately this is pretty
> ugly because there's no way to get gcc to generate a function call,
> but also wrap just the callsite itself with the necessary labels.
> 
> This patch supports functions with 0-4 arguments, and either void or
> returning a value.  64-bit arguments must be split into a pair of
> 32-bit arguments (lower word first).  Small structures are returned in
> registers.

Can you please add some comments to the code explaining this a little?
Best would be perhaps a overview document in Documentation too.

> +#define PVOP_CALL0(__rettype, __op)					\

The __s shouldn't be needed for the macro arguments because
there is no shared name space with the caller.

> +	({								\
> +		__rettype __ret;					\
> +		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
> +			unsigned long long __tmp;			\
> +			unsigned long __ecx;				\
> +			asm volatile(paravirt_alt(PARAVIRT_CALL)	\

Not having the volatile would probably generate better code, but it 
seems much safer for now.

> +				     : "=A" (__tmp), "=c" (__ecx)	\
> +				     : paravirt_type(__op),		\
> +				       paravirt_clobber(CLBR_ANY)	\
> +				     : "memory", "cc");			\

And the cc clobber is also not needed

-Andi

Re: [patch 12/17] Consistently wrap paravirt ops callsites to make them patchable

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> Can you please add some comments to the code explaining this a little?
> Best would be perhaps a overview document in Documentation too.
>   

Yes, OK.

>> +#define PVOP_CALL0(__rettype, __op)					\
>>     
>
> The __s shouldn't be needed for the macro arguments because
> there is no shared name space with the caller.
>   

Yes.  I was more concerned about "op" clashing with variables used
within the macro, but that's not an issue now.

>> +	({								\
>> +		__rettype __ret;					\
>> +		if (sizeof(__rettype) > sizeof(unsigned long)) {	\
>> +			unsigned long long __tmp;			\
>> +			unsigned long __ecx;				\
>> +			asm volatile(paravirt_alt(PARAVIRT_CALL)	\
>>     
>
> Not having the volatile would probably generate better code, but it 
> seems much safer for now.
>   

I think it has to be there, though perhaps the "memory" is sufficient to
make sure all the calls get generated.  We don't want gcc to eliminate
any of these calls because it thinks they can be CSEd.

> And the cc clobber is also not needed
>   

I get conflicting advice about this.  I think Linus mentioned that the
gcc people would prefer it to be there explicitly, even though its
currently implied.


    J

[patch 13/17] add common patching machinery

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-patch-machinery.patch --]
[-- Type: text/plain, Size: 8088 bytes --]

Implement the actual patching machinery.  paravirt_patch_default()
contains the logic to automatically patch a callsite based on a few
simple rules:

 - if the paravirt_op function is paravirt_nop, then patch nops
 - if the paravirt_op function is a jmp target, then jmp to it
 - if the paravirt_op function is callable and doesn't clobber too much
    for the callsite, call it directly

paravirt_patch_default is suitable as a default implementation of
paravirt_ops.patch, will remove most of the expensive indirect calls
in favour of either a direct call or a pile of nops.

Backends may implement their own patcher, however.  There are several
helper functions to help with this:

paravirt_patch_nop	nop out a callsite
paravirt_patch_ignore	leave the callsite as-is
paravirt_patch_call	patch a call if the caller and callee
			have compatible clobbers
paravirt_patch_jmp	patch in a jmp
paravirt_patch_insns	patch some literal instructions over
			the callsite, if they fit

This patch also implements more direct patches for the native case, so
that when running on native hardware many common operations are
implemented inline.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Acked-by: Ingo Molnar <mingo@elte.hu>
---
 arch/i386/kernel/alternative.c |    5 -
 arch/i386/kernel/paravirt.c    |  165 ++++++++++++++++++++++++++++++++--------
 include/asm-i386/paravirt.h    |   11 ++
 3 files changed, 149 insertions(+), 32 deletions(-)

===================================================================
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -361,11 +361,14 @@ void apply_paravirt(struct paravirt_patc
 		used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
 					  p->len);
 
+		BUG_ON(used > p->len);
+
 		/* Pad the rest with nops */
 		nop_out(p->instr + used, p->len - used);
 	}
 
-	/* Sync to be conservative, in case we patched following instructions */
+	/* Sync to be conservative, in case we patched following
+	   instructions */
 	sync_core();
 }
 #endif	/* CONFIG_PARAVIRT */
===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -54,40 +54,143 @@ char *memory_setup(void)
 #define DEF_NATIVE(name, code)					\
 	extern const char start_##name[], end_##name[];		\
 	asm("start_" #name ": " code "; end_" #name ":")
-DEF_NATIVE(cli, "cli");
-DEF_NATIVE(sti, "sti");
-DEF_NATIVE(popf, "push %eax; popf");
-DEF_NATIVE(pushf, "pushf; pop %eax");
+
+DEF_NATIVE(irq_disable, "cli");
+DEF_NATIVE(irq_enable, "sti");
+DEF_NATIVE(restore_fl, "push %eax; popf");
+DEF_NATIVE(save_fl, "pushf; pop %eax");
 DEF_NATIVE(iret, "iret");
-DEF_NATIVE(sti_sysexit, "sti; sysexit");
-
-static const struct native_insns
-{
-	const char *start, *end;
-} native_insns[] = {
-	[PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
-	[PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
-	[PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
-	[PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
-	[PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
-	[PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
-};
+DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
+DEF_NATIVE(read_cr2, "mov %cr2, %eax");
+DEF_NATIVE(write_cr3, "mov %eax, %cr3");
+DEF_NATIVE(read_cr3, "mov %cr3, %eax");
+DEF_NATIVE(clts, "clts");
+DEF_NATIVE(read_tsc, "rdtsc");
+
+DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
+DEF_NATIVE(ud2a, "ud2a");
 
 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
 {
-	unsigned int insn_len;
-
-	/* Don't touch it if we don't have a replacement */
-	if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start)
-		return len;
-
-	insn_len = native_insns[type].end - native_insns[type].start;
-
-	/* Similarly if we can't fit replacement. */
-	if (len < insn_len)
-		return len;
-
-	memcpy(insns, native_insns[type].start, insn_len);
+	const unsigned char *start, *end;
+	unsigned ret;
+
+	switch(type) {
+#define SITE(x)	case PARAVIRT_PATCH(x):	start = start_##x; end = end_##x; goto patch_site
+		SITE(irq_disable);
+		SITE(irq_enable);
+		SITE(restore_fl);
+		SITE(save_fl);
+		SITE(iret);
+		SITE(irq_enable_sysexit);
+		SITE(read_cr2);
+		SITE(read_cr3);
+		SITE(write_cr3);
+		SITE(clts);
+		SITE(read_tsc);
+#undef SITE
+
+	patch_site:
+		ret = paravirt_patch_insns(insns, len, start, end);
+		break;
+
+	case PARAVIRT_PATCH(make_pgd):
+	case PARAVIRT_PATCH(make_pte):
+	case PARAVIRT_PATCH(pgd_val):
+	case PARAVIRT_PATCH(pte_val):
+#ifdef CONFIG_X86_PAE
+	case PARAVIRT_PATCH(make_pmd):
+	case PARAVIRT_PATCH(pmd_val):
+#endif
+		/* These functions end up returning exactly what
+		   they're passed, in the same registers. */
+		ret = paravirt_patch_nop();
+		break;
+
+	default:
+		ret = paravirt_patch_default(type, clobbers, insns, len);
+		break;
+	}
+
+	return ret;
+}
+
+unsigned paravirt_patch_nop(void)
+{
+	return 0;
+}
+
+unsigned paravirt_patch_ignore(unsigned len)
+{
+	return len;
+}
+
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+			     void *site, u16 site_clobbers,
+			     unsigned len)
+{
+	unsigned char *call = site;
+	unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
+
+	if (tgt_clobbers & ~site_clobbers)
+		return len;	/* target would clobber too much for this site */
+	if (len < 5)
+		return len;	/* call too long for patch site */
+
+	*call++ = 0xe8;		/* call */
+	*(unsigned long *)call = delta;
+
+	return 5;
+}
+
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
+{
+	unsigned char *jmp = site;
+	unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
+
+	if (len < 5)
+		return len;	/* call too long for patch site */
+
+	*jmp++ = 0xe9;		/* jmp */
+	*(unsigned long *)jmp = delta;
+
+	return 5;
+}
+
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
+{
+	void *opfunc = *((void **)&paravirt_ops + type);
+	unsigned ret;
+
+	if (opfunc == NULL)
+		/* If there's no function, patch it with a ud2a (BUG) */
+		ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
+	else if (opfunc == paravirt_nop)
+		/* If the operation is a nop, then nop the callsite */
+		ret = paravirt_patch_nop();
+	else if (type == PARAVIRT_PATCH(iret) ||
+		 type == PARAVIRT_PATCH(irq_enable_sysexit))
+		/* If operation requires a jmp, then jmp */
+		ret = paravirt_patch_jmp(opfunc, site, len);
+	else
+		/* Otherwise call the function; assume target could
+		   clobber any caller-save reg */
+		ret = paravirt_patch_call(opfunc, CLBR_ANY,
+					  site, clobbers, len);
+
+	return ret;
+}
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+			      const char *start, const char *end)
+{
+	unsigned insn_len = end - start;
+
+	if (insn_len > len || start == NULL)
+		insn_len = len;
+	else
+		memcpy(site, start, insn_len);
+
 	return insn_len;
 }
 
@@ -110,7 +213,7 @@ static void native_flush_tlb_global(void
 	__native_flush_tlb_global();
 }
 
-static void native_flush_tlb_single(u32 addr)
+static void native_flush_tlb_single(unsigned long addr)
 {
 	__native_flush_tlb_single(addr);
 }
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -933,6 +933,17 @@ struct paravirt_patch_site {
 	u16 clobbers;		/* what registers you may clobber */
 };
 
+unsigned paravirt_patch_nop(void);
+unsigned paravirt_patch_ignore(unsigned len);
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+			     void *site, u16 site_clobbers,
+			     unsigned len);
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len);
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len);
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+			      const char *start, const char *end);
+
 extern struct paravirt_patch_site __start_parainstructions[],
 	__stop_parainstructions[];
 

-- 

[patch 13/17] add common patching machinery

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-patch-machinery.patch --]
[-- Type: text/plain, Size: 8352 bytes --]

Implement the actual patching machinery.  paravirt_patch_default()
contains the logic to automatically patch a callsite based on a few
simple rules:

 - if the paravirt_op function is paravirt_nop, then patch nops
 - if the paravirt_op function is a jmp target, then jmp to it
 - if the paravirt_op function is callable and doesn't clobber too much
    for the callsite, call it directly

paravirt_patch_default is suitable as a default implementation of
paravirt_ops.patch, will remove most of the expensive indirect calls
in favour of either a direct call or a pile of nops.

Backends may implement their own patcher, however.  There are several
helper functions to help with this:

paravirt_patch_nop	nop out a callsite
paravirt_patch_ignore	leave the callsite as-is
paravirt_patch_call	patch a call if the caller and callee
			have compatible clobbers
paravirt_patch_jmp	patch in a jmp
paravirt_patch_insns	patch some literal instructions over
			the callsite, if they fit

This patch also implements more direct patches for the native case, so
that when running on native hardware many common operations are
implemented inline.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Acked-by: Ingo Molnar <mingo@elte.hu>
---
 arch/i386/kernel/alternative.c |    5 -
 arch/i386/kernel/paravirt.c    |  165 ++++++++++++++++++++++++++++++++--------
 include/asm-i386/paravirt.h    |   11 ++
 3 files changed, 149 insertions(+), 32 deletions(-)

===================================================================
--- a/arch/i386/kernel/alternative.c
+++ b/arch/i386/kernel/alternative.c
@@ -361,11 +361,14 @@ void apply_paravirt(struct paravirt_patc
 		used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr,
 					  p->len);
 
+		BUG_ON(used > p->len);
+
 		/* Pad the rest with nops */
 		nop_out(p->instr + used, p->len - used);
 	}
 
-	/* Sync to be conservative, in case we patched following instructions */
+	/* Sync to be conservative, in case we patched following
+	   instructions */
 	sync_core();
 }
 #endif	/* CONFIG_PARAVIRT */
===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -54,40 +54,143 @@ char *memory_setup(void)
 #define DEF_NATIVE(name, code)					\
 	extern const char start_##name[], end_##name[];		\
 	asm("start_" #name ": " code "; end_" #name ":")
-DEF_NATIVE(cli, "cli");
-DEF_NATIVE(sti, "sti");
-DEF_NATIVE(popf, "push %eax; popf");
-DEF_NATIVE(pushf, "pushf; pop %eax");
+
+DEF_NATIVE(irq_disable, "cli");
+DEF_NATIVE(irq_enable, "sti");
+DEF_NATIVE(restore_fl, "push %eax; popf");
+DEF_NATIVE(save_fl, "pushf; pop %eax");
 DEF_NATIVE(iret, "iret");
-DEF_NATIVE(sti_sysexit, "sti; sysexit");
-
-static const struct native_insns
-{
-	const char *start, *end;
-} native_insns[] = {
-	[PARAVIRT_PATCH(irq_disable)] = { start_cli, end_cli },
-	[PARAVIRT_PATCH(irq_enable)] = { start_sti, end_sti },
-	[PARAVIRT_PATCH(restore_fl)] = { start_popf, end_popf },
-	[PARAVIRT_PATCH(save_fl)] = { start_pushf, end_pushf },
-	[PARAVIRT_PATCH(iret)] = { start_iret, end_iret },
-	[PARAVIRT_PATCH(irq_enable_sysexit)] = { start_sti_sysexit, end_sti_sysexit },
-};
+DEF_NATIVE(irq_enable_sysexit, "sti; sysexit");
+DEF_NATIVE(read_cr2, "mov %cr2, %eax");
+DEF_NATIVE(write_cr3, "mov %eax, %cr3");
+DEF_NATIVE(read_cr3, "mov %cr3, %eax");
+DEF_NATIVE(clts, "clts");
+DEF_NATIVE(read_tsc, "rdtsc");
+
+DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli");
+DEF_NATIVE(ud2a, "ud2a");
 
 static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len)
 {
-	unsigned int insn_len;
-
-	/* Don't touch it if we don't have a replacement */
-	if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start)
-		return len;
-
-	insn_len = native_insns[type].end - native_insns[type].start;
-
-	/* Similarly if we can't fit replacement. */
-	if (len < insn_len)
-		return len;
-
-	memcpy(insns, native_insns[type].start, insn_len);
+	const unsigned char *start, *end;
+	unsigned ret;
+
+	switch(type) {
+#define SITE(x)	case PARAVIRT_PATCH(x):	start = start_##x; end = end_##x; goto patch_site
+		SITE(irq_disable);
+		SITE(irq_enable);
+		SITE(restore_fl);
+		SITE(save_fl);
+		SITE(iret);
+		SITE(irq_enable_sysexit);
+		SITE(read_cr2);
+		SITE(read_cr3);
+		SITE(write_cr3);
+		SITE(clts);
+		SITE(read_tsc);
+#undef SITE
+
+	patch_site:
+		ret = paravirt_patch_insns(insns, len, start, end);
+		break;
+
+	case PARAVIRT_PATCH(make_pgd):
+	case PARAVIRT_PATCH(make_pte):
+	case PARAVIRT_PATCH(pgd_val):
+	case PARAVIRT_PATCH(pte_val):
+#ifdef CONFIG_X86_PAE
+	case PARAVIRT_PATCH(make_pmd):
+	case PARAVIRT_PATCH(pmd_val):
+#endif
+		/* These functions end up returning exactly what
+		   they're passed, in the same registers. */
+		ret = paravirt_patch_nop();
+		break;
+
+	default:
+		ret = paravirt_patch_default(type, clobbers, insns, len);
+		break;
+	}
+
+	return ret;
+}
+
+unsigned paravirt_patch_nop(void)
+{
+	return 0;
+}
+
+unsigned paravirt_patch_ignore(unsigned len)
+{
+	return len;
+}
+
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+			     void *site, u16 site_clobbers,
+			     unsigned len)
+{
+	unsigned char *call = site;
+	unsigned long delta = (unsigned long)target - (unsigned long)(call+5);
+
+	if (tgt_clobbers & ~site_clobbers)
+		return len;	/* target would clobber too much for this site */
+	if (len < 5)
+		return len;	/* call too long for patch site */
+
+	*call++ = 0xe8;		/* call */
+	*(unsigned long *)call = delta;
+
+	return 5;
+}
+
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len)
+{
+	unsigned char *jmp = site;
+	unsigned long delta = (unsigned long)target - (unsigned long)(jmp+5);
+
+	if (len < 5)
+		return len;	/* call too long for patch site */
+
+	*jmp++ = 0xe9;		/* jmp */
+	*(unsigned long *)jmp = delta;
+
+	return 5;
+}
+
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len)
+{
+	void *opfunc = *((void **)&paravirt_ops + type);
+	unsigned ret;
+
+	if (opfunc == NULL)
+		/* If there's no function, patch it with a ud2a (BUG) */
+		ret = paravirt_patch_insns(site, len, start_ud2a, end_ud2a);
+	else if (opfunc == paravirt_nop)
+		/* If the operation is a nop, then nop the callsite */
+		ret = paravirt_patch_nop();
+	else if (type == PARAVIRT_PATCH(iret) ||
+		 type == PARAVIRT_PATCH(irq_enable_sysexit))
+		/* If operation requires a jmp, then jmp */
+		ret = paravirt_patch_jmp(opfunc, site, len);
+	else
+		/* Otherwise call the function; assume target could
+		   clobber any caller-save reg */
+		ret = paravirt_patch_call(opfunc, CLBR_ANY,
+					  site, clobbers, len);
+
+	return ret;
+}
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+			      const char *start, const char *end)
+{
+	unsigned insn_len = end - start;
+
+	if (insn_len > len || start == NULL)
+		insn_len = len;
+	else
+		memcpy(site, start, insn_len);
+
 	return insn_len;
 }
 
@@ -110,7 +213,7 @@ static void native_flush_tlb_global(void
 	__native_flush_tlb_global();
 }
 
-static void native_flush_tlb_single(u32 addr)
+static void native_flush_tlb_single(unsigned long addr)
 {
 	__native_flush_tlb_single(addr);
 }
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -933,6 +933,17 @@ struct paravirt_patch_site {
 	u16 clobbers;		/* what registers you may clobber */
 };
 
+unsigned paravirt_patch_nop(void);
+unsigned paravirt_patch_ignore(unsigned len);
+unsigned paravirt_patch_call(void *target, u16 tgt_clobbers,
+			     void *site, u16 site_clobbers,
+			     unsigned len);
+unsigned paravirt_patch_jmp(void *target, void *site, unsigned len);
+unsigned paravirt_patch_default(u8 type, u16 clobbers, void *site, unsigned len);
+
+unsigned paravirt_patch_insns(void *site, unsigned len,
+			      const char *start, const char *end);
+
 extern struct paravirt_patch_site __start_parainstructions[],
 	__stop_parainstructions[];
 

-- 

[patch 14/17] add flush_tlb_others paravirt_op

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-flush_tlb_others.patch --]
[-- Type: text/plain, Size: 5109 bytes --]

This patch adds a pv_op for flush_tlb_others.  Linux running on native
hardware uses cross-CPU IPIs to flush the TLB on any CPU which may
have a particular mm's pagetable entries cached in its TLB.  This is
inefficient in a paravirtualized environment, since the hypervisor
knows which real CPUs actually contain cached mappings, which may be a
small subset of a guest's VCPUs.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

---
 arch/i386/kernel/paravirt.c |    1 +
 arch/i386/kernel/smp.c      |   15 ++++++++-------
 include/asm-i386/paravirt.h |    9 +++++++++
 include/asm-i386/tlbflush.h |   19 +++++++++++++++++--
 4 files changed, 35 insertions(+), 9 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -301,6 +301,7 @@ struct paravirt_ops paravirt_ops = {
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
+	.flush_tlb_others = native_flush_tlb_others,
 
 	.map_pt_hook = paravirt_nop,
 
===================================================================
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -256,7 +256,6 @@ static struct mm_struct * flush_mm;
 static struct mm_struct * flush_mm;
 static unsigned long flush_va;
 static DEFINE_SPINLOCK(tlbstate_lock);
-#define FLUSH_ALL	0xffffffff
 
 /*
  * We cannot call mmdrop() because we are in interrupt context, 
@@ -338,7 +337,7 @@ fastcall void smp_invalidate_interrupt(s
 		 
 	if (flush_mm == per_cpu(cpu_tlbstate, cpu).active_mm) {
 		if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK) {
-			if (flush_va == FLUSH_ALL)
+			if (flush_va == TLB_FLUSH_ALL)
 				local_flush_tlb();
 			else
 				__flush_tlb_one(flush_va);
@@ -353,9 +352,11 @@ out:
 	put_cpu_no_resched();
 }
 
-static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
-						unsigned long va)
-{
+void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
+			     unsigned long va)
+{
+	cpumask_t cpumask = *cpumaskp;
+
 	/*
 	 * A couple of (to be removed) sanity checks:
 	 *
@@ -417,7 +418,7 @@ void flush_tlb_current_task(void)
 
 	local_flush_tlb();
 	if (!cpus_empty(cpu_mask))
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
 	preempt_enable();
 }
 
@@ -436,7 +437,7 @@ void flush_tlb_mm (struct mm_struct * mm
 			leave_mm(smp_processor_id());
 	}
 	if (!cpus_empty(cpu_mask))
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
 
 	preempt_enable();
 }
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -15,6 +15,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
+#include <linux/cpumask.h>
 
 struct thread_struct;
 struct Xgt_desc_struct;
@@ -125,6 +126,8 @@ struct paravirt_ops
 	void (*flush_tlb_user)(void);
 	void (*flush_tlb_kernel)(void);
 	void (*flush_tlb_single)(unsigned long addr);
+	void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm,
+				 unsigned long va);
 
 	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
@@ -731,6 +734,12 @@ static inline void __flush_tlb_single(un
 	PVOP_VCALL1(flush_tlb_single, addr);
 }
 
+static inline void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
+				    unsigned long va)
+{
+	PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va);
+}
+
 static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
 {
 	PVOP_VCALL3(map_pt_hook, type, va, pfn);
===================================================================
--- a/include/asm-i386/tlbflush.h
+++ b/include/asm-i386/tlbflush.h
@@ -79,10 +79,14 @@
  *  - flush_tlb_range(vma, start, end) flushes a range of pages
  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
  *  - flush_tlb_pgtables(mm, start, end) flushes a range of page tables
+ *  - flush_tlb_others(cpumask, mm, va) flushes a TLBs on other cpus
  *
  * ..but the i386 has somewhat limited tlb flushing capabilities,
  * and page-granular flushes are available only on i486 and up.
  */
+
+#define TLB_FLUSH_ALL	0xffffffff
+
 
 #ifndef CONFIG_SMP
 
@@ -110,7 +114,12 @@ static inline void flush_tlb_range(struc
 		__flush_tlb();
 }
 
-#else
+static inline void native_flush_tlb_others(const cpumask_t *cpumask,
+					   struct mm_struct *mm, unsigned long va)
+{
+}
+
+#else  /* SMP */
 
 #include <asm/smp.h>
 
@@ -129,6 +138,9 @@ static inline void flush_tlb_range(struc
 	flush_tlb_mm(vma->vm_mm);
 }
 
+void native_flush_tlb_others(const cpumask_t *cpumask, struct mm_struct *mm,
+			     unsigned long va);
+
 #define TLBSTATE_OK	1
 #define TLBSTATE_LAZY	2
 
@@ -139,8 +151,11 @@ struct tlb_state
 	char __cacheline_padding[L1_CACHE_BYTES-8];
 };
 DECLARE_PER_CPU(struct tlb_state, cpu_tlbstate);
+#endif	/* SMP */
 
-
+#ifndef CONFIG_PARAVIRT
+#define flush_tlb_others(mask, mm, va)		\
+	native_flush_tlb_others(&mask, mm, va)
 #endif
 
 #define flush_tlb_kernel_range(start, end) flush_tlb_all()

-- 

[patch 14/17] add flush_tlb_others paravirt_op

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-flush_tlb_others.patch --]
[-- Type: text/plain, Size: 5276 bytes --]

This patch adds a pv_op for flush_tlb_others.  Linux running on native
hardware uses cross-CPU IPIs to flush the TLB on any CPU which may
have a particular mm's pagetable entries cached in its TLB.  This is
inefficient in a paravirtualized environment, since the hypervisor
knows which real CPUs actually contain cached mappings, which may be a
small subset of a guest's VCPUs.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>

---
 arch/i386/kernel/paravirt.c |    1 +
 arch/i386/kernel/smp.c      |   15 ++++++++-------
 include/asm-i386/paravirt.h |    9 +++++++++
 include/asm-i386/tlbflush.h |   19 +++++++++++++++++--
 4 files changed, 35 insertions(+), 9 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -301,6 +301,7 @@ struct paravirt_ops paravirt_ops = {
 	.flush_tlb_user = native_flush_tlb,
 	.flush_tlb_kernel = native_flush_tlb_global,
 	.flush_tlb_single = native_flush_tlb_single,
+	.flush_tlb_others = native_flush_tlb_others,
 
 	.map_pt_hook = paravirt_nop,
 
===================================================================
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -256,7 +256,6 @@ static struct mm_struct * flush_mm;
 static struct mm_struct * flush_mm;
 static unsigned long flush_va;
 static DEFINE_SPINLOCK(tlbstate_lock);
-#define FLUSH_ALL	0xffffffff
 
 /*
  * We cannot call mmdrop() because we are in interrupt context, 
@@ -338,7 +337,7 @@ fastcall void smp_invalidate_interrupt(s
 		 
 	if (flush_mm == per_cpu(cpu_tlbstate, cpu).active_mm) {
 		if (per_cpu(cpu_tlbstate, cpu).state == TLBSTATE_OK) {
-			if (flush_va == FLUSH_ALL)
+			if (flush_va == TLB_FLUSH_ALL)
 				local_flush_tlb();
 			else
 				__flush_tlb_one(flush_va);
@@ -353,9 +352,11 @@ out:
 	put_cpu_no_resched();
 }
 
-static void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
-						unsigned long va)
-{
+void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
+			     unsigned long va)
+{
+	cpumask_t cpumask = *cpumaskp;
+
 	/*
 	 * A couple of (to be removed) sanity checks:
 	 *
@@ -417,7 +418,7 @@ void flush_tlb_current_task(void)
 
 	local_flush_tlb();
 	if (!cpus_empty(cpu_mask))
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
 	preempt_enable();
 }
 
@@ -436,7 +437,7 @@ void flush_tlb_mm (struct mm_struct * mm
 			leave_mm(smp_processor_id());
 	}
 	if (!cpus_empty(cpu_mask))
-		flush_tlb_others(cpu_mask, mm, FLUSH_ALL);
+		flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
 
 	preempt_enable();
 }
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -15,6 +15,7 @@
 
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
+#include <linux/cpumask.h>
 
 struct thread_struct;
 struct Xgt_desc_struct;
@@ -125,6 +126,8 @@ struct paravirt_ops
 	void (*flush_tlb_user)(void);
 	void (*flush_tlb_kernel)(void);
 	void (*flush_tlb_single)(unsigned long addr);
+	void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm,
+				 unsigned long va);
 
 	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
@@ -731,6 +734,12 @@ static inline void __flush_tlb_single(un
 	PVOP_VCALL1(flush_tlb_single, addr);
 }
 
+static inline void flush_tlb_others(cpumask_t cpumask, struct mm_struct *mm,
+				    unsigned long va)
+{
+	PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va);
+}
+
 static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
 {
 	PVOP_VCALL3(map_pt_hook, type, va, pfn);
===================================================================
--- a/include/asm-i386/tlbflush.h
+++ b/include/asm-i386/tlbflush.h
@@ -79,10 +79,14 @@
  *  - flush_tlb_range(vma, start, end) flushes a range of pages
  *  - flush_tlb_kernel_range(start, end) flushes a range of kernel pages
  *  - flush_tlb_pgtables(mm, start, end) flushes a range of page tables
+ *  - flush_tlb_others(cpumask, mm, va) flushes a TLBs on other cpus
  *
  * ..but the i386 has somewhat limited tlb flushing capabilities,
  * and page-granular flushes are available only on i486 and up.
  */
+
+#define TLB_FLUSH_ALL	0xffffffff
+
 
 #ifndef CONFIG_SMP
 
@@ -110,7 +114,12 @@ static inline void flush_tlb_range(struc
 		__flush_tlb();
 }
 
-#else
+static inline void native_flush_tlb_others(const cpumask_t *cpumask,
+					   struct mm_struct *mm, unsigned long va)
+{
+}
+
+#else  /* SMP */
 
 #include <asm/smp.h>
 
@@ -129,6 +138,9 @@ static inline void flush_tlb_range(struc
 	flush_tlb_mm(vma->vm_mm);
 }
 
+void native_flush_tlb_others(const cpumask_t *cpumask, struct mm_struct *mm,
+			     unsigned long va);
+
 #define TLBSTATE_OK	1
 #define TLBSTATE_LAZY	2
 
@@ -139,8 +151,11 @@ struct tlb_state
 	char __cacheline_padding[L1_CACHE_BYTES-8];
 };
 DECLARE_PER_CPU(struct tlb_state, cpu_tlbstate);
+#endif	/* SMP */
 
-
+#ifndef CONFIG_PARAVIRT
+#define flush_tlb_others(mask, mm, va)		\
+	native_flush_tlb_others(&mask, mm, va)
 #endif
 
 #define flush_tlb_kernel_range(start, end) flush_tlb_all()

-- 

[patch 15/17] revert map_pt_hook.

[Jeremy Fitzhardinge]

[-- Attachment #1: revert-map_pt_hook.patch --]
[-- Type: text/plain, Size: 3560 bytes --]

Back out the map_pt_hook to clear the way for kmap_atomic_pte.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/paravirt.c |    2 --
 arch/i386/kernel/vmi.c      |    2 ++
 include/asm-i386/paravirt.h |    7 -------
 include/asm-i386/pgtable.h  |   23 ++++-------------------
 4 files changed, 6 insertions(+), 28 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -303,8 +303,6 @@ struct paravirt_ops paravirt_ops = {
 	.flush_tlb_single = native_flush_tlb_single,
 	.flush_tlb_others = native_flush_tlb_others,
 
-	.map_pt_hook = paravirt_nop,
-
 	.alloc_pt = paravirt_nop,
 	.alloc_pd = paravirt_nop,
 	.alloc_pd_clone = paravirt_nop,
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -819,8 +819,10 @@ static inline int __init activate_vmi(vo
 		paravirt_ops.release_pt = vmi_release_pt;
 		paravirt_ops.release_pd = vmi_release_pd;
 	}
+#if 0
 	para_wrap(map_pt_hook, vmi_map_pt_hook, set_linear_mapping,
 		  SetLinearMapping);
+#endif
 
 	/*
 	 * These MUST always be patched.  Don't support indirect jumps
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -128,8 +128,6 @@ struct paravirt_ops
 	void (*flush_tlb_single)(unsigned long addr);
 	void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm,
 				 unsigned long va);
-
-	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
 	void (*alloc_pt)(u32 pfn);
 	void (*alloc_pd)(u32 pfn);
@@ -740,11 +738,6 @@ static inline void flush_tlb_others(cpum
 	PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va);
 }
 
-static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
-{
-	PVOP_VCALL3(map_pt_hook, type, va, pfn);
-}
-
 static inline void paravirt_alloc_pt(unsigned pfn)
 {
 	PVOP_VCALL1(alloc_pt, pfn);
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -272,7 +272,6 @@ static inline void vmalloc_sync_all(void
  */
 #define pte_update(mm, addr, ptep)		do { } while (0)
 #define pte_update_defer(mm, addr, ptep)	do { } while (0)
-#define paravirt_map_pt_hook(slot, va, pfn)	do { } while (0)
 
 #define raw_ptep_get_and_clear(xp)     native_ptep_get_and_clear(xp)
 #endif
@@ -481,24 +480,10 @@ extern pte_t *lookup_address(unsigned lo
 #endif
 
 #if defined(CONFIG_HIGHPTE)
-#define pte_offset_map(dir, address)				\
-({								\
-	pte_t *__ptep;						\
-	unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;	   	\
-	__ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE0);\
-	paravirt_map_pt_hook(KM_PTE0,__ptep, pfn);		\
-	__ptep = __ptep + pte_index(address);			\
-	__ptep;							\
-})
-#define pte_offset_map_nested(dir, address)			\
-({								\
-	pte_t *__ptep;						\
-	unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;	   	\
-	__ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE1);\
-	paravirt_map_pt_hook(KM_PTE1,__ptep, pfn);		\
-	__ptep = __ptep + pte_index(address);			\
-	__ptep;							\
-})
+#define pte_offset_map(dir, address) \
+	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
+#define pte_offset_map_nested(dir, address) \
+	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
 #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
 #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
 #else

-- 

[patch 15/17] revert map_pt_hook.

[Jeremy Fitzhardinge]

[-- Attachment #1: revert-map_pt_hook.patch --]
[-- Type: text/plain, Size: 3661 bytes --]

Back out the map_pt_hook to clear the way for kmap_atomic_pte.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/paravirt.c |    2 --
 arch/i386/kernel/vmi.c      |    2 ++
 include/asm-i386/paravirt.h |    7 -------
 include/asm-i386/pgtable.h  |   23 ++++-------------------
 4 files changed, 6 insertions(+), 28 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -303,8 +303,6 @@ struct paravirt_ops paravirt_ops = {
 	.flush_tlb_single = native_flush_tlb_single,
 	.flush_tlb_others = native_flush_tlb_others,
 
-	.map_pt_hook = paravirt_nop,
-
 	.alloc_pt = paravirt_nop,
 	.alloc_pd = paravirt_nop,
 	.alloc_pd_clone = paravirt_nop,
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -819,8 +819,10 @@ static inline int __init activate_vmi(vo
 		paravirt_ops.release_pt = vmi_release_pt;
 		paravirt_ops.release_pd = vmi_release_pd;
 	}
+#if 0
 	para_wrap(map_pt_hook, vmi_map_pt_hook, set_linear_mapping,
 		  SetLinearMapping);
+#endif
 
 	/*
 	 * These MUST always be patched.  Don't support indirect jumps
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -128,8 +128,6 @@ struct paravirt_ops
 	void (*flush_tlb_single)(unsigned long addr);
 	void (*flush_tlb_others)(const cpumask_t *cpus, struct mm_struct *mm,
 				 unsigned long va);
-
-	void (*map_pt_hook)(int type, pte_t *va, u32 pfn);
 
 	void (*alloc_pt)(u32 pfn);
 	void (*alloc_pd)(u32 pfn);
@@ -740,11 +738,6 @@ static inline void flush_tlb_others(cpum
 	PVOP_VCALL3(flush_tlb_others, &cpumask, mm, va);
 }
 
-static inline void paravirt_map_pt_hook(int type, pte_t *va, u32 pfn)
-{
-	PVOP_VCALL3(map_pt_hook, type, va, pfn);
-}
-
 static inline void paravirt_alloc_pt(unsigned pfn)
 {
 	PVOP_VCALL1(alloc_pt, pfn);
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -272,7 +272,6 @@ static inline void vmalloc_sync_all(void
  */
 #define pte_update(mm, addr, ptep)		do { } while (0)
 #define pte_update_defer(mm, addr, ptep)	do { } while (0)
-#define paravirt_map_pt_hook(slot, va, pfn)	do { } while (0)
 
 #define raw_ptep_get_and_clear(xp)     native_ptep_get_and_clear(xp)
 #endif
@@ -481,24 +480,10 @@ extern pte_t *lookup_address(unsigned lo
 #endif
 
 #if defined(CONFIG_HIGHPTE)
-#define pte_offset_map(dir, address)				\
-({								\
-	pte_t *__ptep;						\
-	unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;	   	\
-	__ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE0);\
-	paravirt_map_pt_hook(KM_PTE0,__ptep, pfn);		\
-	__ptep = __ptep + pte_index(address);			\
-	__ptep;							\
-})
-#define pte_offset_map_nested(dir, address)			\
-({								\
-	pte_t *__ptep;						\
-	unsigned pfn = pmd_val(*(dir)) >> PAGE_SHIFT;	   	\
-	__ptep = (pte_t *)kmap_atomic(pfn_to_page(pfn),KM_PTE1);\
-	paravirt_map_pt_hook(KM_PTE1,__ptep, pfn);		\
-	__ptep = __ptep + pte_index(address);			\
-	__ptep;							\
-})
+#define pte_offset_map(dir, address) \
+	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
+#define pte_offset_map_nested(dir, address) \
+	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
 #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
 #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
 #else

-- 

[patch 16/17] add kmap_atomic_pte for mapping highpte pages

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-kmap_atomic_pte.patch --]
[-- Type: text/plain, Size: 7040 bytes --]

Xen and VMI both have special requirements when mapping a highmem pte
page into the kernel address space.  These can be dealt with by adding
a new kmap_atomic_pte() function for mapping highptes, and hooking it
into the paravirt_ops infrastructure.

Xen specifically wants to map the pte page RO, so this patch exposes a
helper function, kmap_atomic_prot, which maps the page with the
specified page protections.

This also adds a kmap_flush_unused() function to clear out the cached
kmap mappings.  Xen needs this to clear out any potential stray RW
mappings of pages which will become part of a pagetable.

[ Zach - vmi.c will need some attention after this patch.  It wasn't
  immediately obvious to me what needs to be done. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>

---
 arch/i386/kernel/paravirt.c |    7 +++++++
 arch/i386/mm/highmem.c      |    9 +++++++--
 include/asm-i386/highmem.h  |   11 +++++++++++
 include/asm-i386/paravirt.h |   13 ++++++++++++-
 include/asm-i386/pgtable.h  |    4 ++--
 include/linux/highmem.h     |    6 ++++++
 mm/highmem.c                |    9 +++++++++
 7 files changed, 54 insertions(+), 5 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -20,6 +20,7 @@
 #include <linux/efi.h>
 #include <linux/bcd.h>
 #include <linux/start_kernel.h>
+#include <linux/highmem.h>
 
 #include <asm/bug.h>
 #include <asm/paravirt.h>
@@ -318,6 +319,12 @@ struct paravirt_ops paravirt_ops = {
 
 	.ptep_get_and_clear = native_ptep_get_and_clear,
 
+#ifdef CONFIG_HIGHPTE
+	.kmap_atomic_pte = native_kmap_atomic_pte,
+#else
+	.kmap_atomic_pte = paravirt_nop,
+#endif
+
 #ifdef CONFIG_X86_PAE
 	.set_pte_atomic = native_set_pte_atomic,
 	.set_pte_present = native_set_pte_present,
===================================================================
--- a/arch/i386/mm/highmem.c
+++ b/arch/i386/mm/highmem.c
@@ -26,7 +26,7 @@ void kunmap(struct page *page)
  * However when holding an atomic kmap is is not legal to sleep, so atomic
  * kmaps are appropriate for short, tight code paths only.
  */
-void *kmap_atomic(struct page *page, enum km_type type)
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr;
@@ -41,9 +41,14 @@ void *kmap_atomic(struct page *page, enu
 		return page_address(page);
 
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
 
 	return (void*) vaddr;
+}
+
+void *kmap_atomic(struct page *page, enum km_type type)
+{
+	return kmap_atomic_prot(page, type, kmap_prot);
 }
 
 void kunmap_atomic(void *kvaddr, enum km_type type)
===================================================================
--- a/include/asm-i386/highmem.h
+++ b/include/asm-i386/highmem.h
@@ -24,6 +24,7 @@
 #include <linux/threads.h>
 #include <asm/kmap_types.h>
 #include <asm/tlbflush.h>
+#include <asm/paravirt.h>
 
 /* declarations for highmem.c */
 extern unsigned long highstart_pfn, highend_pfn;
@@ -67,10 +68,20 @@ extern void FASTCALL(kunmap_high(struct 
 
 void *kmap(struct page *page);
 void kunmap(struct page *page);
+void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot);
 void *kmap_atomic(struct page *page, enum km_type type);
 void kunmap_atomic(void *kvaddr, enum km_type type);
 void *kmap_atomic_pfn(unsigned long pfn, enum km_type type);
 struct page *kmap_atomic_to_page(void *ptr);
+
+static inline void *native_kmap_atomic_pte(struct page *page, enum km_type type)
+{
+	return kmap_atomic(page, type);
+}
+
+#ifndef CONFIG_PARAVIRT
+#define kmap_atomic_pte(page, type)	kmap_atomic(page, type)
+#endif
 
 #define flush_cache_kmaps()	do { } while (0)
 
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -16,7 +16,9 @@
 #ifndef __ASSEMBLY__
 #include <linux/types.h>
 #include <linux/cpumask.h>
-
+#include <asm/kmap_types.h>
+
+struct page;
 struct thread_struct;
 struct Xgt_desc_struct;
 struct tss_struct;
@@ -143,6 +145,8 @@ struct paravirt_ops
 	void (*pte_update_defer)(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 
  	pte_t (*ptep_get_and_clear)(pte_t *ptep);
+
+	void *(*kmap_atomic_pte)(struct page *page, enum km_type type);
 
 #ifdef CONFIG_X86_PAE
 	void (*set_pte_atomic)(pte_t *ptep, pte_t pteval);
@@ -768,6 +772,13 @@ static inline void paravirt_release_pd(u
 	PVOP_VCALL1(release_pd, pfn);
 }
 
+static inline void *kmap_atomic_pte(struct page *page, enum km_type type)
+{
+	unsigned long ret;
+	ret = PVOP_CALL2(unsigned long, kmap_atomic_pte, page, type);
+	return (void *)ret;
+}
+
 static inline void pte_update(struct mm_struct *mm, unsigned long addr,
 			      pte_t *ptep)
 {
===================================================================
--- a/include/asm-i386/pgtable.h
+++ b/include/asm-i386/pgtable.h
@@ -481,9 +481,9 @@ extern pte_t *lookup_address(unsigned lo
 
 #if defined(CONFIG_HIGHPTE)
 #define pte_offset_map(dir, address) \
-	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
+	((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE0) + pte_index(address))
 #define pte_offset_map_nested(dir, address) \
-	((pte_t *)kmap_atomic(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
+	((pte_t *)kmap_atomic_pte(pmd_page(*(dir)),KM_PTE1) + pte_index(address))
 #define pte_unmap(pte) kunmap_atomic(pte, KM_PTE0)
 #define pte_unmap_nested(pte) kunmap_atomic(pte, KM_PTE1)
 #else
===================================================================
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -27,6 +27,8 @@ unsigned int nr_free_highpages(void);
 unsigned int nr_free_highpages(void);
 extern unsigned long totalhigh_pages;
 
+void kmap_flush_unused(void);
+
 #else /* CONFIG_HIGHMEM */
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
@@ -44,9 +46,13 @@ static inline void *kmap(struct page *pa
 
 #define kmap_atomic(page, idx) \
 	({ pagefault_disable(); page_address(page); })
+#define kmap_atomic_prot(page, idx, prot)	kmap_atomic(page, idx)
+
 #define kunmap_atomic(addr, idx)	do { pagefault_enable(); } while (0)
 #define kmap_atomic_pfn(pfn, idx)	kmap_atomic(pfn_to_page(pfn), (idx))
 #define kmap_atomic_to_page(ptr)	virt_to_page(ptr)
+
+#define kmap_flush_unused()	do {} while(0)
 #endif
 
 #endif /* CONFIG_HIGHMEM */
===================================================================
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -97,6 +97,15 @@ static void flush_all_zero_pkmaps(void)
 		set_page_address(page, NULL);
 	}
 	flush_tlb_kernel_range(PKMAP_ADDR(0), PKMAP_ADDR(LAST_PKMAP));
+}
+
+/* Flush all unused kmap mappings in order to remove stray
+   mappings. */
+void kmap_flush_unused(void)
+{
+	spin_lock(&kmap_lock);
+	flush_all_zero_pkmaps();
+	spin_unlock(&kmap_lock);
 }
 
 static inline unsigned long map_new_virtual(struct page *page)

-- 

Re: [patch 16/17] add kmap_atomic_pte for mapping highpte pages

[Andi Kleen]

> +}
> +
> +/* Flush all unused kmap mappings in order to remove stray
> +   mappings. */
> +void kmap_flush_unused(void)
> +{
> +	spin_lock(&kmap_lock);
> +	flush_all_zero_pkmaps();
> +	spin_unlock(&kmap_lock);
>  }

Who calls this now?

-Andi

Re: [patch 16/17] add kmap_atomic_pte for mapping highpte pages

[Andi Kleen]

> +}
> +
> +/* Flush all unused kmap mappings in order to remove stray
> +   mappings. */
> +void kmap_flush_unused(void)
> +{
> +	spin_lock(&kmap_lock);
> +	flush_all_zero_pkmaps();
> +	spin_unlock(&kmap_lock);
>  }

Who calls this now?

-Andi

Re: [patch 16/17] add kmap_atomic_pte for mapping highpte pages

[Jeremy Fitzhardinge]

Andi Kleen wrote:
>> +}
>> +
>> +/* Flush all unused kmap mappings in order to remove stray
>> +   mappings. */
>> +void kmap_flush_unused(void)
>> +{
>> +	spin_lock(&kmap_lock);
>> +	flush_all_zero_pkmaps();
>> +	spin_unlock(&kmap_lock);
>>  }
>>     
>
> Who calls this now?

Nobody in kernel, or in this patchset.  The Xen code calls it to make
sure there are no stray RW mappings of a page it has freshly allocated
for use in a pagetable.

    J

Re: [patch 16/17] add kmap_atomic_pte for mapping highpte pages

[Jeremy Fitzhardinge]

Andi Kleen wrote:
>> +}
>> +
>> +/* Flush all unused kmap mappings in order to remove stray
>> +   mappings. */
>> +void kmap_flush_unused(void)
>> +{
>> +	spin_lock(&kmap_lock);
>> +	flush_all_zero_pkmaps();
>> +	spin_unlock(&kmap_lock);
>>  }
>>     
>
> Who calls this now?

Nobody in kernel, or in this patchset.  The Xen code calls it to make
sure there are no stray RW mappings of a page it has freshly allocated
for use in a pagetable.

    J

[patch 17/17] Add a sched_clock paravirt_op

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-sched-clock.patch --]
[-- Type: text/plain, Size: 7888 bytes --]

The tsc-based get_scheduled_cycles interface is not a good match for
Xen's runstate accounting, which reports everything in nanoseconds.

This patch replaces this interface with a sched_clock interface, which
matches both Xen and VMI's requirements.

In order to do this, we:
   1. replace get_scheduled_cycles with sched_clock
   2. hoist cycles_2_ns into a common header
   3. update vmi accordingly

One thing to note: because sched_clock is implemented as a weak
function in kernel/sched.c, we must define a real function in order to
override this weak binding.  This means the usual paravirt_ops
technique of using an inline function won't work in this case.


Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Cc: john stultz <johnstul@us.ibm.com>

---
 arch/i386/kernel/paravirt.c    |    2 -
 arch/i386/kernel/sched-clock.c |   39 ++++++++++++++--------------------
 arch/i386/kernel/vmi.c         |    2 -
 arch/i386/kernel/vmitime.c     |    6 ++---
 include/asm-i386/paravirt.h    |    7 ++++--
 include/asm-i386/timer.h       |   45 +++++++++++++++++++++++++++++++++++++++-
 include/asm-i386/vmi_time.h    |    2 -
 7 files changed, 71 insertions(+), 32 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -269,7 +269,7 @@ struct paravirt_ops paravirt_ops = {
 	.write_msr = native_write_msr_safe,
 	.read_tsc = native_read_tsc,
 	.read_pmc = native_read_pmc,
-	.get_scheduled_cycles = native_read_tsc,
+	.sched_clock = native_sched_clock,
 	.get_cpu_khz = native_calculate_cpu_khz,
 	.load_tr_desc = native_load_tr_desc,
 	.set_ldt = native_set_ldt,
===================================================================
--- a/arch/i386/kernel/sched-clock.c
+++ b/arch/i386/kernel/sched-clock.c
@@ -37,26 +37,7 @@
 
 #define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
 
-struct sc_data {
-	unsigned int cyc2ns_scale;
-	unsigned char unstable;
-	unsigned long long last_tsc;
-	unsigned long long ns_base;
-};
-
-static DEFINE_PER_CPU(struct sc_data, sc_data);
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
-	const struct sc_data *sc = &__get_cpu_var(sc_data);
-	unsigned long long ns;
-
-	cyc -= sc->last_tsc;
-	ns = (cyc * sc->cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-	ns += sc->ns_base;
-
-	return ns;
-}
+DEFINE_PER_CPU(struct sc_data, sc_data);
 
 /*
  * Scheduler clock - returns current time in nanosec units.
@@ -66,7 +47,7 @@ static inline unsigned long long cycles_
  * [1] no attempt to stop CPU instruction reordering, which can hit
  * in a 100 instruction window or so.
  */
-unsigned long long sched_clock(void)
+unsigned long long native_sched_clock(void)
 {
 	unsigned long long r;
 	const struct sc_data *sc = &get_cpu_var(sc_data);
@@ -75,7 +56,7 @@ unsigned long long sched_clock(void)
 		/* TBD find a cheaper fallback timer than this */
 		r = ktime_to_ns(ktime_get());
 	} else {
-		get_scheduled_cycles(r);
+		rdtscll(r);
 		r = cycles_2_ns(r);
 	}
 
@@ -83,6 +64,18 @@ unsigned long long sched_clock(void)
 
 	return r;
 }
+
+/* We need to define a real function for sched_clock, to override the
+   weak default version */
+#ifdef CONFIG_PARAVIRT
+unsigned long long sched_clock(void)
+{
+	return paravirt_sched_clock();
+}
+#else
+unsigned long long sched_clock(void)
+	__attribute__((alias("native_sched_clock")));
+#endif
 
 /* Resync with new CPU frequency */
 static void resync_sc_freq(struct sc_data *sc, unsigned int newfreq)
@@ -95,7 +88,7 @@ static void resync_sc_freq(struct sc_dat
 	   because sched_clock callers should be able to tolerate small
 	   errors. */
 	sc->ns_base = ktime_to_ns(ktime_get());
-	get_scheduled_cycles(sc->last_tsc);
+	rdtscll(sc->last_tsc);
 	sc->cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR) / newfreq;
 	sc->unstable = 0;
 }
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -866,7 +866,7 @@ static inline int __init activate_vmi(vo
 		paravirt_ops.setup_boot_clock = vmi_timer_setup_boot_alarm;
 		paravirt_ops.setup_secondary_clock = vmi_timer_setup_secondary_alarm;
 #endif
-		paravirt_ops.get_scheduled_cycles = vmi_get_sched_cycles;
+		paravirt_ops.sched_clock = vmi_sched_clock;
  		paravirt_ops.get_cpu_khz = vmi_cpu_khz;
 
 		/* We have true wallclock functions; disable CMOS clock sync */
===================================================================
--- a/arch/i386/kernel/vmitime.c
+++ b/arch/i386/kernel/vmitime.c
@@ -163,9 +163,9 @@ int vmi_set_wallclock(unsigned long now)
 	return -1;
 }
 
-unsigned long long vmi_get_sched_cycles(void)
-{
-	return read_available_cycles();
+unsigned long long vmi_sched_clock(void)
+{
+	return cycles_2_ns(read_available_cycles());
 }
 
 unsigned long vmi_cpu_khz(void)
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -88,7 +88,7 @@ struct paravirt_ops
 
 	u64 (*read_tsc)(void);
 	u64 (*read_pmc)(void);
- 	u64 (*get_scheduled_cycles)(void);
+ 	unsigned long long (*sched_clock)(void);
 	unsigned long (*get_cpu_khz)(void);
 
 	void (*load_tr_desc)(void);
@@ -529,7 +529,10 @@ static inline void halt(void)
 
 #define rdtscll(val) (val = PVOP_CALL0(u64, read_tsc))
 
-#define get_scheduled_cycles(val) (val = paravirt_ops.get_scheduled_cycles())
+static inline unsigned long long paravirt_sched_clock(void)
+{
+	return PVOP_CALL0(unsigned long long, sched_clock);
+}
 #define calculate_cpu_khz() (paravirt_ops.get_cpu_khz())
 
 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
===================================================================
--- a/include/asm-i386/timer.h
+++ b/include/asm-i386/timer.h
@@ -15,8 +15,51 @@ extern int recalibrate_cpu_khz(void);
 extern int recalibrate_cpu_khz(void);
 
 #ifndef CONFIG_PARAVIRT
-#define get_scheduled_cycles(val) rdtscll(val)
 #define calculate_cpu_khz() native_calculate_cpu_khz()
 #endif
 
+/* Accellerators for sched_clock()
+ * convert from cycles(64bits) => nanoseconds (64bits)
+ *  basic equation:
+ *		ns = cycles / (freq / ns_per_sec)
+ *		ns = cycles * (ns_per_sec / freq)
+ *		ns = cycles * (10^9 / (cpu_khz * 10^3))
+ *		ns = cycles * (10^6 / cpu_khz)
+ *
+ *	Then we use scaling math (suggested by george@mvista.com) to get:
+ *		ns = cycles * (10^6 * SC / cpu_khz) / SC
+ *		ns = cycles * cyc2ns_scale / SC
+ *
+ *	And since SC is a constant power of two, we can convert the div
+ *  into a shift.
+ *
+ *  We can use khz divisor instead of mhz to keep a better percision, since
+ *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
+ *  (mathieu.desnoyers@polymtl.ca)
+ *
+ *			-johnstul@us.ibm.com "math is hard, lets go shopping!"
+ */
+struct sc_data {
+	unsigned int cyc2ns_scale;
+	unsigned char unstable;
+	unsigned long long last_tsc;
+	unsigned long long ns_base;
+};
+
+DECLARE_PER_CPU(struct sc_data, sc_data);
+
+#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+
+static inline unsigned long long cycles_2_ns(unsigned long long cyc)
+{
+	const struct sc_data *sc = &__get_cpu_var(sc_data);
+	unsigned long long ns;
+
+	cyc -= sc->last_tsc;
+	ns = (cyc * sc->cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+	ns += sc->ns_base;
+
+	return ns;
+}
+
 #endif
===================================================================
--- a/include/asm-i386/vmi_time.h
+++ b/include/asm-i386/vmi_time.h
@@ -49,7 +49,7 @@ extern void __init vmi_time_init(void);
 extern void __init vmi_time_init(void);
 extern unsigned long vmi_get_wallclock(void);
 extern int vmi_set_wallclock(unsigned long now);
-extern unsigned long long vmi_get_sched_cycles(void);
+extern unsigned long long vmi_sched_clock(void);
 extern unsigned long vmi_cpu_khz(void);
 
 #ifdef CONFIG_X86_LOCAL_APIC

-- 

[patch 17/17] Add a sched_clock paravirt_op

[Jeremy Fitzhardinge]

[-- Attachment #1: paravirt-sched-clock.patch --]
[-- Type: text/plain, Size: 8128 bytes --]

The tsc-based get_scheduled_cycles interface is not a good match for
Xen's runstate accounting, which reports everything in nanoseconds.

This patch replaces this interface with a sched_clock interface, which
matches both Xen and VMI's requirements.

In order to do this, we:
   1. replace get_scheduled_cycles with sched_clock
   2. hoist cycles_2_ns into a common header
   3. update vmi accordingly

One thing to note: because sched_clock is implemented as a weak
function in kernel/sched.c, we must define a real function in order to
override this weak binding.  This means the usual paravirt_ops
technique of using an inline function won't work in this case.


Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Cc: john stultz <johnstul@us.ibm.com>

---
 arch/i386/kernel/paravirt.c    |    2 -
 arch/i386/kernel/sched-clock.c |   39 ++++++++++++++--------------------
 arch/i386/kernel/vmi.c         |    2 -
 arch/i386/kernel/vmitime.c     |    6 ++---
 include/asm-i386/paravirt.h    |    7 ++++--
 include/asm-i386/timer.h       |   45 +++++++++++++++++++++++++++++++++++++++-
 include/asm-i386/vmi_time.h    |    2 -
 7 files changed, 71 insertions(+), 32 deletions(-)

===================================================================
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -269,7 +269,7 @@ struct paravirt_ops paravirt_ops = {
 	.write_msr = native_write_msr_safe,
 	.read_tsc = native_read_tsc,
 	.read_pmc = native_read_pmc,
-	.get_scheduled_cycles = native_read_tsc,
+	.sched_clock = native_sched_clock,
 	.get_cpu_khz = native_calculate_cpu_khz,
 	.load_tr_desc = native_load_tr_desc,
 	.set_ldt = native_set_ldt,
===================================================================
--- a/arch/i386/kernel/sched-clock.c
+++ b/arch/i386/kernel/sched-clock.c
@@ -37,26 +37,7 @@
 
 #define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
 
-struct sc_data {
-	unsigned int cyc2ns_scale;
-	unsigned char unstable;
-	unsigned long long last_tsc;
-	unsigned long long ns_base;
-};
-
-static DEFINE_PER_CPU(struct sc_data, sc_data);
-
-static inline unsigned long long cycles_2_ns(unsigned long long cyc)
-{
-	const struct sc_data *sc = &__get_cpu_var(sc_data);
-	unsigned long long ns;
-
-	cyc -= sc->last_tsc;
-	ns = (cyc * sc->cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
-	ns += sc->ns_base;
-
-	return ns;
-}
+DEFINE_PER_CPU(struct sc_data, sc_data);
 
 /*
  * Scheduler clock - returns current time in nanosec units.
@@ -66,7 +47,7 @@ static inline unsigned long long cycles_
  * [1] no attempt to stop CPU instruction reordering, which can hit
  * in a 100 instruction window or so.
  */
-unsigned long long sched_clock(void)
+unsigned long long native_sched_clock(void)
 {
 	unsigned long long r;
 	const struct sc_data *sc = &get_cpu_var(sc_data);
@@ -75,7 +56,7 @@ unsigned long long sched_clock(void)
 		/* TBD find a cheaper fallback timer than this */
 		r = ktime_to_ns(ktime_get());
 	} else {
-		get_scheduled_cycles(r);
+		rdtscll(r);
 		r = cycles_2_ns(r);
 	}
 
@@ -83,6 +64,18 @@ unsigned long long sched_clock(void)
 
 	return r;
 }
+
+/* We need to define a real function for sched_clock, to override the
+   weak default version */
+#ifdef CONFIG_PARAVIRT
+unsigned long long sched_clock(void)
+{
+	return paravirt_sched_clock();
+}
+#else
+unsigned long long sched_clock(void)
+	__attribute__((alias("native_sched_clock")));
+#endif
 
 /* Resync with new CPU frequency */
 static void resync_sc_freq(struct sc_data *sc, unsigned int newfreq)
@@ -95,7 +88,7 @@ static void resync_sc_freq(struct sc_dat
 	   because sched_clock callers should be able to tolerate small
 	   errors. */
 	sc->ns_base = ktime_to_ns(ktime_get());
-	get_scheduled_cycles(sc->last_tsc);
+	rdtscll(sc->last_tsc);
 	sc->cyc2ns_scale = (1000000 << CYC2NS_SCALE_FACTOR) / newfreq;
 	sc->unstable = 0;
 }
===================================================================
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -866,7 +866,7 @@ static inline int __init activate_vmi(vo
 		paravirt_ops.setup_boot_clock = vmi_timer_setup_boot_alarm;
 		paravirt_ops.setup_secondary_clock = vmi_timer_setup_secondary_alarm;
 #endif
-		paravirt_ops.get_scheduled_cycles = vmi_get_sched_cycles;
+		paravirt_ops.sched_clock = vmi_sched_clock;
  		paravirt_ops.get_cpu_khz = vmi_cpu_khz;
 
 		/* We have true wallclock functions; disable CMOS clock sync */
===================================================================
--- a/arch/i386/kernel/vmitime.c
+++ b/arch/i386/kernel/vmitime.c
@@ -163,9 +163,9 @@ int vmi_set_wallclock(unsigned long now)
 	return -1;
 }
 
-unsigned long long vmi_get_sched_cycles(void)
-{
-	return read_available_cycles();
+unsigned long long vmi_sched_clock(void)
+{
+	return cycles_2_ns(read_available_cycles());
 }
 
 unsigned long vmi_cpu_khz(void)
===================================================================
--- a/include/asm-i386/paravirt.h
+++ b/include/asm-i386/paravirt.h
@@ -88,7 +88,7 @@ struct paravirt_ops
 
 	u64 (*read_tsc)(void);
 	u64 (*read_pmc)(void);
- 	u64 (*get_scheduled_cycles)(void);
+ 	unsigned long long (*sched_clock)(void);
 	unsigned long (*get_cpu_khz)(void);
 
 	void (*load_tr_desc)(void);
@@ -529,7 +529,10 @@ static inline void halt(void)
 
 #define rdtscll(val) (val = PVOP_CALL0(u64, read_tsc))
 
-#define get_scheduled_cycles(val) (val = paravirt_ops.get_scheduled_cycles())
+static inline unsigned long long paravirt_sched_clock(void)
+{
+	return PVOP_CALL0(unsigned long long, sched_clock);
+}
 #define calculate_cpu_khz() (paravirt_ops.get_cpu_khz())
 
 #define write_tsc(val1,val2) wrmsr(0x10, val1, val2)
===================================================================
--- a/include/asm-i386/timer.h
+++ b/include/asm-i386/timer.h
@@ -15,8 +15,51 @@ extern int recalibrate_cpu_khz(void);
 extern int recalibrate_cpu_khz(void);
 
 #ifndef CONFIG_PARAVIRT
-#define get_scheduled_cycles(val) rdtscll(val)
 #define calculate_cpu_khz() native_calculate_cpu_khz()
 #endif
 
+/* Accellerators for sched_clock()
+ * convert from cycles(64bits) => nanoseconds (64bits)
+ *  basic equation:
+ *		ns = cycles / (freq / ns_per_sec)
+ *		ns = cycles * (ns_per_sec / freq)
+ *		ns = cycles * (10^9 / (cpu_khz * 10^3))
+ *		ns = cycles * (10^6 / cpu_khz)
+ *
+ *	Then we use scaling math (suggested by george@mvista.com) to get:
+ *		ns = cycles * (10^6 * SC / cpu_khz) / SC
+ *		ns = cycles * cyc2ns_scale / SC
+ *
+ *	And since SC is a constant power of two, we can convert the div
+ *  into a shift.
+ *
+ *  We can use khz divisor instead of mhz to keep a better percision, since
+ *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
+ *  (mathieu.desnoyers@polymtl.ca)
+ *
+ *			-johnstul@us.ibm.com "math is hard, lets go shopping!"
+ */
+struct sc_data {
+	unsigned int cyc2ns_scale;
+	unsigned char unstable;
+	unsigned long long last_tsc;
+	unsigned long long ns_base;
+};
+
+DECLARE_PER_CPU(struct sc_data, sc_data);
+
+#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
+
+static inline unsigned long long cycles_2_ns(unsigned long long cyc)
+{
+	const struct sc_data *sc = &__get_cpu_var(sc_data);
+	unsigned long long ns;
+
+	cyc -= sc->last_tsc;
+	ns = (cyc * sc->cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
+	ns += sc->ns_base;
+
+	return ns;
+}
+
 #endif
===================================================================
--- a/include/asm-i386/vmi_time.h
+++ b/include/asm-i386/vmi_time.h
@@ -49,7 +49,7 @@ extern void __init vmi_time_init(void);
 extern void __init vmi_time_init(void);
 extern unsigned long vmi_get_wallclock(void);
 extern int vmi_set_wallclock(unsigned long now);
-extern unsigned long long vmi_get_sched_cycles(void);
+extern unsigned long long vmi_sched_clock(void);
 extern unsigned long vmi_cpu_khz(void);
 
 #ifdef CONFIG_X86_LOCAL_APIC

-- 

Re: [patch 17/17] Add a sched_clock paravirt_op

[Andi Kleen]

On Monday 02 April 2007 07:57, Jeremy Fitzhardinge wrote:
> The tsc-based get_scheduled_cycles interface is not a good match for
> Xen's runstate accounting, which reports everything in nanoseconds.
> 
> This patch replaces this interface with a sched_clock interface, which
> matches both Xen and VMI's requirements.
> 
> In order to do this, we:
>    1. replace get_scheduled_cycles with sched_clock
>    2. hoist cycles_2_ns into a common header
>    3. update vmi accordingly
> 
> One thing to note: because sched_clock is implemented as a weak
> function in kernel/sched.c, we must define a real function in order to
> override this weak binding.  This means the usual paravirt_ops
> technique of using an inline function won't work in this case.

I think it would be much cleaner if you didn't implement your own sched_clock,
but you adjust ns_base/last_tsc to account for your lost cycles.
This could be done cleanly by adding a new function to sched-clock.c
Possibly such a function could be used by other parts of the kernel
in the future too.

-Andi

Re: [patch 17/17] Add a sched_clock paravirt_op

[Andi Kleen]

On Monday 02 April 2007 07:57, Jeremy Fitzhardinge wrote:
> The tsc-based get_scheduled_cycles interface is not a good match for
> Xen's runstate accounting, which reports everything in nanoseconds.
> 
> This patch replaces this interface with a sched_clock interface, which
> matches both Xen and VMI's requirements.
> 
> In order to do this, we:
>    1. replace get_scheduled_cycles with sched_clock
>    2. hoist cycles_2_ns into a common header
>    3. update vmi accordingly
> 
> One thing to note: because sched_clock is implemented as a weak
> function in kernel/sched.c, we must define a real function in order to
> override this weak binding.  This means the usual paravirt_ops
> technique of using an inline function won't work in this case.

I think it would be much cleaner if you didn't implement your own sched_clock,
but you adjust ns_base/last_tsc to account for your lost cycles.
This could be done cleanly by adding a new function to sched-clock.c
Possibly such a function could be used by other parts of the kernel
in the future too.

-Andi

Re: [patch 17/17] Add a sched_clock paravirt_op

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> I think it would be much cleaner if you didn't implement your own sched_clock,
> but you adjust ns_base/last_tsc to account for your lost cycles.
> This could be done cleanly by adding a new function to sched-clock.c
> Possibly such a function could be used by other parts of the kernel
> in the future too.
>   

Cleaner how?  This seems pretty straightforward to me.  Xen can return a
clock measuring unstolen nanoseconds, which maps directly to the
sched_clock interface, doesn't need any of the existing sched_clock
code.  I suppose I could map the Xen interface onto some abstract
"cycles" notion and hook it into the tsc machinery, but it seems like it
would be a forced fit.  In general, my approach has been to choose the
higher-level interface over a lower-level one, all other things being equal.

The only reason I hoisted the cycles_2_ns stuff was for vmi.  It returns
a tsc-like cycles interface, and so it can make use of the existing
cycles_2_ns code (though I don't think a changing timebase is an issue).

    J

Re: [patch 17/17] Add a sched_clock paravirt_op

[Andi Kleen]

On Monday 02 April 2007 08:47, Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> > I think it would be much cleaner if you didn't implement your own sched_clock,
> > but you adjust ns_base/last_tsc to account for your lost cycles.
> > This could be done cleanly by adding a new function to sched-clock.c
> > Possibly such a function could be used by other parts of the kernel
> > in the future too.
> >   
> 
> Cleaner how?  This seems pretty to me.  Xen can return a
> clock measuring unstolen nanoseconds, 

Do you also get a clock for stolen nanoseconds? 

> which maps directly to the 
> sched_clock interface, doesn't need any of the existing sched_clock
> code.  I suppose I could map the Xen interface onto some abstract
> "cycles" notion and hook it into the tsc machinery, but it seems like it
> would be a forced fit.  In general, my approach has been to choose the
> higher-level interface over a lower-level one, all other things being equal.

No need for cycles, you could just subtract the stolen ns if you
can get those.

-Andi

Re: [patch 17/17] Add a sched_clock paravirt_op

[Andi Kleen]

On Monday 02 April 2007 08:47, Jeremy Fitzhardinge wrote:
> Andi Kleen wrote:
> > I think it would be much cleaner if you didn't implement your own sched_clock,
> > but you adjust ns_base/last_tsc to account for your lost cycles.
> > This could be done cleanly by adding a new function to sched-clock.c
> > Possibly such a function could be used by other parts of the kernel
> > in the future too.
> >   
> 
> Cleaner how?  This seems pretty to me.  Xen can return a
> clock measuring unstolen nanoseconds, 

Do you also get a clock for stolen nanoseconds? 

> which maps directly to the 
> sched_clock interface, doesn't need any of the existing sched_clock
> code.  I suppose I could map the Xen interface onto some abstract
> "cycles" notion and hook it into the tsc machinery, but it seems like it
> would be a forced fit.  In general, my approach has been to choose the
> higher-level interface over a lower-level one, all other things being equal.

No need for cycles, you could just subtract the stolen ns if you
can get those.

-Andi

Re: [patch 17/17] Add a sched_clock paravirt_op

[Jeremy Fitzhardinge]

Andi Kleen wrote:
> Do you also get a clock for stolen nanoseconds? 
>   

What you actually get is how many ns the CPU spent in each state. 
Stolen is runnable+offline.

> No need for cycles, you could just subtract the stolen ns if you
> can get those.

It just seems like a simpler interface to just allow overriding
sched_clock, rather than exposing sched_clock's internals and fiddling
with those.  There's really nothing in the existing sched_clock which
can be profitably reused in the Xen case.  VMI can make use of the
cycles_2_ns conversion, which is why I made it available for its use.

To be specific, this is the whole Xen sched_clock function:

/* Xen sched_clock implementation.  Returns the number of RUNNING ns */
unsigned long long xen_sched_clock(void)
{
	struct vcpu_runstate_info state;
	cycle_t now;
	unsigned long long ret;

	preempt_disable();

	now = xen_clocksource_read();
	get_runstate_snapshot(&state);
	WARN_ON(state.state != RUNSTATE_running);

	ret = state.time[RUNSTATE_running] + (now - state.state_entry_time);

	preempt_enable();

	return ret;
}


    J