[PATCH v2 00/10] Hyper-V: praravirtualized remote TLB flushing and hypercall improvements

[PATCH v2 00/10] Hyper-V: praravirtualized remote TLB flushing and hypercall improvements

[Vitaly Kuznetsov]

Changes since v1:
- Add a patch to build code in arch/x86/hyperv/ only when CONFIG_HYPERV is
  set.
- Add a patch to get maximum virtual/logical processor on Hyper-V.
- Add additional clobbers to hypercalls [Jork Loeser]
- Add variable header size support to rep hypercalls.
- Rename vmbus_cpu_number_to_vp_number -> hv_cpu_number_to_vp_number
  [K. Y. Srinivasan]
- Remove spinlocks from hyperv_flush_tlb_others() [Jork Loeser]
- Account for mm==NULL in hyperv_flush_tlb_others() [Simon Xiao]
- Add support for HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls
  to support >64 vCPUs [K. Y. Srinivasan, Jork Loeser]
- Move hyperv.h to arch-specific place [Steven Rostedt]
- Rebased to the latest char-misc-next tree.

Original descriptions:

Hyper-V supports hypercalls for doing local and remote TLB flushing and
gives its guests hints when using hypercall is preferred. While doing
hypercalls for local TLB flushes is probably not practical (and is not
being suggested by modern Hyper-V versions) remote TLB flush with a
hypercall brings significant improvement.

To test the series I wrote a special 'TLB trasher': on a 16 vCPU guest I
was creating 32 threads which were doing 100000 mmap/munmaps each on some
big file. Here are the results:

Before:
# time ./pthread_mmap ./randfile 
real	3m44.994s
user	0m3.829s
sys	3m36.323s

After:
# time ./pthread_mmap ./randfile 
real	2m57.145s
user	0m3.797s
sys	2m34.812s

This series brings a number of small improvements along the way: fast
hypercall implementation and using it for event signaling, rep hypercalls
implementation, hyperv tracing subsystem (which only traces the newly added
remote TLB flush for now).

Vitaly Kuznetsov (10):
  x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set
  x86/hyper-v: stash the max number of virtual/logical processor
  x86/hyper-v: make hv_do_hypercall() inline
  x86/hyper-v: fast hypercall implementation
  hyper-v: use fast hypercall for HVCALL_SIGNAL_EVENT
  x86/hyper-v: implement rep hypercalls
  hyper-v: globalize vp_index
  x86/hyper-v: use hypercall for remote TLB flush
  x86/hyper-v: support extended CPU ranges for TLB flush hypercalls
  tracing/hyper-v: trace hyperv_mmu_flush_tlb_others()

 MAINTAINERS                         |   1 +
 arch/x86/Kbuild                     |   4 +-
 arch/x86/hyperv/Makefile            |   2 +-
 arch/x86/hyperv/hv_init.c           |  90 ++++++------
 arch/x86/hyperv/mmu.c               | 270 ++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h     | 148 +++++++++++++++++++-
 arch/x86/include/asm/trace/hyperv.h |  34 +++++
 arch/x86/include/uapi/asm/hyperv.h  |  36 +++++
 arch/x86/kernel/cpu/mshyperv.c      |  14 +-
 drivers/hv/channel_mgmt.c           |  22 ++-
 drivers/hv/connection.c             |   8 +-
 drivers/hv/hv.c                     |   9 --
 drivers/hv/hyperv_vmbus.h           |  11 --
 drivers/hv/vmbus_drv.c              |  17 ---
 drivers/pci/host/pci-hyperv.c       |   4 +-
 include/linux/hyperv.h              |  21 ++-
 16 files changed, 567 insertions(+), 124 deletions(-)
 create mode 100644 arch/x86/hyperv/mmu.c
 create mode 100644 arch/x86/include/asm/trace/hyperv.h

-- 
2.9.3

[PATCH v2 01/10] x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set

[Vitaly Kuznetsov]

Code is arch/x86/hyperv/ is only needed when CONFIG_HYPERV is set, the
'basic' support and detection lives in arch/x86/kernel/cpu/mshyperv.c
which is included when CONFIG_HYPERVISOR_GUEST is set.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/Kbuild                 | 4 +++-
 arch/x86/include/asm/mshyperv.h | 9 ++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild
index 586b786..3fa0a3c 100644
--- a/arch/x86/Kbuild
+++ b/arch/x86/Kbuild
@@ -8,7 +8,9 @@ obj-$(CONFIG_KVM) += kvm/
 obj-$(CONFIG_XEN) += xen/
 
 # Hyper-V paravirtualization support
-obj-$(CONFIG_HYPERVISOR_GUEST) += hyperv/
+ifdef CONFIG_HYPERV
+obj-y += hyperv/
+endif
 
 # lguest paravirtualization support
 obj-$(CONFIG_LGUEST_GUEST) += lguest/
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 7c9c895..e654956 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -175,5 +175,12 @@ void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
 void hyperv_cleanup(void);
-#endif
+#else /* CONFIG_HYPERV */
+static inline void hyperv_init(void) {}
+static inline bool hv_is_hypercall_page_setup(void)
+{
+	return false;
+}
+static inline hyperv_cleanup(void) {}
+#endif /* CONFIG_HYPERV */
 #endif
-- 
2.9.3

[PATCH v2 02/10] x86/hyper-v: stash the max number of virtual/logical processor

[Vitaly Kuznetsov]

Max virtual processor will be needed for 'extended' hypercalls supporting
more than 64 vCPUs. While on it, unify on 'Hyper-V' in mshyperv.c as we
currently have a mix, report acquired misc features as well.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/include/asm/mshyperv.h |  2 ++
 arch/x86/kernel/cpu/mshyperv.c  | 13 ++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index e654956..be3872a 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -29,6 +29,8 @@ struct ms_hyperv_info {
 	u32 features;
 	u32 misc_features;
 	u32 hints;
+	u32 max_vp_index;
+	u32 max_lp_index;
 };
 
 extern struct ms_hyperv_info ms_hyperv;
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 04cb8d3..a8b4765 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -175,9 +175,16 @@ static void __init ms_hyperv_init_platform(void)
 	ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES);
 	ms_hyperv.hints    = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO);
 
-	pr_info("HyperV: features 0x%x, hints 0x%x\n",
+	pr_info("Hyper-V: features 0x%x, hints 0x%x\n",
 		ms_hyperv.features, ms_hyperv.hints);
 
+	ms_hyperv.max_vp_index = cpuid_eax(HVCPUID_IMPLEMENTATION_LIMITS);
+	ms_hyperv.max_lp_index = cpuid_ebx(HVCPUID_IMPLEMENTATION_LIMITS);
+
+	pr_info("Hyper-V: max %d virtual processors, %d logical processors\n",
+		ms_hyperv.max_vp_index, ms_hyperv.max_lp_index);
+
+
 	/*
 	 * Extract host information.
 	 */
@@ -203,7 +210,7 @@ static void __init ms_hyperv_init_platform(void)
 		rdmsrl(HV_X64_MSR_APIC_FREQUENCY, hv_lapic_frequency);
 		hv_lapic_frequency = div_u64(hv_lapic_frequency, HZ);
 		lapic_timer_frequency = hv_lapic_frequency;
-		pr_info("HyperV: LAPIC Timer Frequency: %#x\n",
+		pr_info("Hyper-V: LAPIC Timer Frequency: %#x\n",
 			lapic_timer_frequency);
 	}
 
@@ -237,7 +244,7 @@ static void __init ms_hyperv_init_platform(void)
 }
 
 const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {
-	.name			= "Microsoft HyperV",
+	.name			= "Microsoft Hyper-V",
 	.detect			= ms_hyperv_platform,
 	.init_platform		= ms_hyperv_init_platform,
 };
-- 
2.9.3

[PATCH v2 03/10] x86/hyper-v: make hv_do_hypercall() inline

[Vitaly Kuznetsov]

We have only three call sites for hv_do_hypercall() and we're going to
change HVCALL_SIGNAL_EVENT to doing fast hypercall so we can inline this
function for optimization.

Hyper-V top level functional specification states that r9-r11 registers
and flags may be clobbered by the hypervisor during hypercall and with
inlining this is somewhat important, add the clobbers.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
- Clobber memory, rcx/rdx for x86 and ecx for x86 are now specified with
  '+' as hypervisor may overwrite them [Jork Loeser]
- Simplify x86 version a bit.
---
 arch/x86/hyperv/hv_init.c       | 54 ++++-------------------------------------
 arch/x86/include/asm/mshyperv.h | 43 ++++++++++++++++++++++++++++++++
 drivers/hv/connection.c         |  2 ++
 include/linux/hyperv.h          |  1 -
 4 files changed, 50 insertions(+), 50 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index ecaa3f3..7d961d4 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -98,7 +98,8 @@ static struct clocksource hyperv_cs_msr = {
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void *hypercall_pg;
+void *hv_hypercall_pg;
+EXPORT_SYMBOL_GPL(hv_hypercall_pg);
 struct clocksource *hyperv_cs;
 EXPORT_SYMBOL_GPL(hyperv_cs);
 
@@ -125,15 +126,15 @@ void hyperv_init(void)
 	guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
 
-	hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
-	if (hypercall_pg == NULL) {
+	hv_hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
+	if (hv_hypercall_pg == NULL) {
 		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 		return;
 	}
 
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 	hypercall_msr.enable = 1;
-	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
+	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
 	/*
@@ -190,51 +191,6 @@ void hyperv_cleanup(void)
 }
 EXPORT_SYMBOL_GPL(hyperv_cleanup);
 
-/*
- * hv_do_hypercall- Invoke the specified hypercall
- */
-u64 hv_do_hypercall(u64 control, void *input, void *output)
-{
-	u64 input_address = (input) ? virt_to_phys(input) : 0;
-	u64 output_address = (output) ? virt_to_phys(output) : 0;
-#ifdef CONFIG_X86_64
-	u64 hv_status = 0;
-
-	if (!hypercall_pg)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
-	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
-			     "c" (control), "d" (input_address),
-			     "m" (hypercall_pg));
-
-	return hv_status;
-
-#else
-
-	u32 control_hi = control >> 32;
-	u32 control_lo = control & 0xFFFFFFFF;
-	u32 hv_status_hi = 1;
-	u32 hv_status_lo = 1;
-	u32 input_address_hi = input_address >> 32;
-	u32 input_address_lo = input_address & 0xFFFFFFFF;
-	u32 output_address_hi = output_address >> 32;
-	u32 output_address_lo = output_address & 0xFFFFFFFF;
-
-	if (!hypercall_pg)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
-			      "=a"(hv_status_lo) : "d" (control_hi),
-			      "a" (control_lo), "b" (input_address_hi),
-			      "c" (input_address_lo), "D"(output_address_hi),
-			      "S"(output_address_lo), "m" (hypercall_pg));
-
-	return hv_status_lo | ((u64)hv_status_hi << 32);
-#endif /* !x86_64 */
-}
-EXPORT_SYMBOL_GPL(hv_do_hypercall);
-
 void hyperv_report_panic(struct pt_regs *regs)
 {
 	static bool panic_reported;
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index be3872a..a9c6c10 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -172,6 +172,49 @@ void hv_remove_crash_handler(void);
 
 #if IS_ENABLED(CONFIG_HYPERV)
 extern struct clocksource *hyperv_cs;
+extern void *hv_hypercall_pg;
+
+static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
+{
+	u64 input_address = (input) ? virt_to_phys(input) : 0;
+	u64 output_address = (output) ? virt_to_phys(output) : 0;
+#ifdef CONFIG_X86_64
+	u64 hv_status;
+
+	if (!hv_hypercall_pg)
+		return (u64)ULLONG_MAX;
+
+	__asm__ __volatile__("mov %3, %%r8\n"
+			     "call *%4"
+			     : "=a" (hv_status),
+			       "+c" (control), "+d" (input_address)
+			     :  "r" (output_address), "m" (hv_hypercall_pg)
+			     : "cc", "memory", "r8", "r9", "r10", "r11");
+
+	return hv_status;
+
+#else
+	u32 control_hi = control >> 32;
+	u32 control_lo = control & 0xFFFFFFFF;
+	u32 input_address_hi = input_address >> 32;
+	u32 input_address_lo = input_address & 0xFFFFFFFF;
+	u32 output_address_hi = output_address >> 32;
+	u32 output_address_lo = output_address & 0xFFFFFFFF;
+
+	if (!hv_hypercall_pg)
+		return (u64)ULLONG_MAX;
+
+	__asm__ __volatile__("call *%6"
+			     : "+a" (control_lo), "+d" (control_hi),
+			       "+c" (input_address_lo)
+			     : "b" (input_address_hi),
+			       "D"(output_address_hi), "S"(output_address_lo),
+			       "m" (hv_hypercall_pg)
+			     : "cc", "memory");
+
+	return control_lo | ((u64)control_hi << 32);
+#endif /* !x86_64 */
+}
 
 void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index fce27fb..cf77c7f 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -32,6 +32,8 @@
 #include <linux/hyperv.h>
 #include <linux/export.h>
 #include <asm/hyperv.h>
+#include <asm/mshyperv.h>
+
 #include "hyperv_vmbus.h"
 
 
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index f681f7b..677f084 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1188,7 +1188,6 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 			bool fb_overlap_ok);
 void vmbus_free_mmio(resource_size_t start, resource_size_t size);
 int vmbus_cpu_number_to_vp_number(int cpu_number);
-u64 hv_do_hypercall(u64 control, void *input, void *output);
 
 /*
  * GUID definitions of various offer types - services offered to the guest.
-- 
2.9.3

[PATCH v2 04/10] x86/hyper-v: fast hypercall implementation

[Vitaly Kuznetsov]

Hyper-V supports 'fast' hypercalls when all parameters are passed through
registers. Implement an inline version of a simpliest of these calls:
hypercall with one 8-byte input and no output.

Proper hypercall input interface (struct hv_hypercall_input) definition is
added as well.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
- rcx/rdx on x86_64 and ecx on x86 are now specified with '+' as hypervisor
  is allowed to write there, clobber esi/edi on x86 [Jork Loeser].
- Had to introduce input1_hi/input1_lo to make gcc happy as specifying '+'
  for something like 'input1>>32' doesn't work.
---
 arch/x86/include/asm/mshyperv.h    | 39 ++++++++++++++++++++++++++++++++++++++
 arch/x86/include/uapi/asm/hyperv.h | 19 +++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index a9c6c10..7b9b404 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -216,6 +216,45 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
 #endif /* !x86_64 */
 }
 
+/* Fast hypercall with 8 bytes of input and no output */
+static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
+{
+	union hv_hypercall_input control = {0};
+
+	control.code = code;
+	control.fast = 1;
+#ifdef CONFIG_X86_64
+	{
+		u64 hv_status;
+
+		__asm__ __volatile__("call *%3"
+				     : "=a" (hv_status),
+				       "+c" (control.as_uint64), "+d" (input1)
+				     : "m" (hv_hypercall_pg)
+				     : "cc", "r8", "r9", "r10", "r11");
+		return hv_status;
+	}
+#else
+	{
+		u32 hv_status_hi, hv_status_lo;
+		u32 input1_hi = (u32)(input1 >> 32);
+		u32 input1_lo = (u32)input1;
+
+		__asm__ __volatile__ ("call *%6"
+				      : "=d"(hv_status_hi),
+					"=a"(hv_status_lo),
+					"+c"(input1_lo)
+				      :	"d" (control.as_uint32_hi),
+					"a" (control.as_uint32_lo),
+					"b" (input1_hi),
+					"m" (hv_hypercall_pg)
+				      : "cc", "edi", "esi");
+
+		return hv_status_lo | ((u64)hv_status_hi << 32);
+	}
+#endif
+}
+
 void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 432df4b..c87e900 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -256,6 +256,25 @@
 #define HV_PROCESSOR_POWER_STATE_C2		2
 #define HV_PROCESSOR_POWER_STATE_C3		3
 
+/* Hypercall interface */
+union hv_hypercall_input {
+	u64 as_uint64;
+	struct {
+		__u32 as_uint32_lo;
+		__u32 as_uint32_hi;
+	};
+	struct {
+		__u64 code:16;
+		__u64 fast:1;
+		__u64 varhead_size:10;
+		__u64 reserved1:5;
+		__u64 rep_count:12;
+		__u64 reserved2:4;
+		__u64 rep_start:12;
+		__u64 reserved3:4;
+	};
+};
+
 /* hypercall status code */
 #define HV_STATUS_SUCCESS			0
 #define HV_STATUS_INVALID_HYPERCALL_CODE	2
-- 
2.9.3

[PATCH v2 05/10] hyper-v: use fast hypercall for HVCALL_SIGNAL_EVENT

[Vitaly Kuznetsov]

We need to pass only 8 bytes of input for HvSignalEvent which makes it a
perfect fit for fast hypercall. hv_input_signal_event_buffer is not needed
any more and hv_input_signal_event is converted to union for convenience.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 drivers/hv/channel_mgmt.c | 15 +++++----------
 drivers/hv/connection.c   |  3 ++-
 include/linux/hyperv.h    | 19 ++++++++-----------
 3 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 735f936..6cfa297 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -804,20 +804,15 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 	/*
 	 * Setup state for signalling the host.
 	 */
-	newchannel->sig_event = (struct hv_input_signal_event *)
-				(ALIGN((unsigned long)
-				&newchannel->sig_buf,
-				HV_HYPERCALL_PARAM_ALIGN));
-
-	newchannel->sig_event->connectionid.asu32 = 0;
-	newchannel->sig_event->connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
-	newchannel->sig_event->flag_number = 0;
-	newchannel->sig_event->rsvdz = 0;
+	newchannel->sig_event.connectionid.asu32 = 0;
+	newchannel->sig_event.connectionid.u.id = VMBUS_EVENT_CONNECTION_ID;
+	newchannel->sig_event.flag_number = 0;
+	newchannel->sig_event.rsvdz = 0;
 
 	if (vmbus_proto_version != VERSION_WS2008) {
 		newchannel->is_dedicated_interrupt =
 				(offer->is_dedicated_interrupt != 0);
-		newchannel->sig_event->connectionid.u.id =
+		newchannel->sig_event.connectionid.u.id =
 				offer->connection_id;
 	}
 
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index cf77c7f..545f2a4 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -405,6 +405,7 @@ void vmbus_set_event(struct vmbus_channel *channel)
 	if (!channel->is_dedicated_interrupt)
 		vmbus_send_interrupt(child_relid);
 
-	hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
+	hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT,
+			      channel->sig_event.as_uint64);
 }
 EXPORT_SYMBOL_GPL(vmbus_set_event);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 677f084..5d6777c 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -678,15 +678,13 @@ union hv_connection_id {
 };
 
 /* Definition of the hv_signal_event hypercall input structure. */
-struct hv_input_signal_event {
-	union hv_connection_id connectionid;
-	u16 flag_number;
-	u16 rsvdz;
-};
-
-struct hv_input_signal_event_buffer {
-	u64 align8;
-	struct hv_input_signal_event event;
+union hv_input_signal_event {
+	u64 as_uint64;
+	struct {
+		union hv_connection_id connectionid;
+		u16 flag_number;
+		u16 rsvdz;
+	};
 };
 
 enum hv_numa_policy {
@@ -771,8 +769,7 @@ struct vmbus_channel {
 	} callback_mode;
 
 	bool is_dedicated_interrupt;
-	struct hv_input_signal_event_buffer sig_buf;
-	struct hv_input_signal_event *sig_event;
+	union hv_input_signal_event sig_event;
 
 	/*
 	 * Starting with win8, this field will be used to specify
-- 
2.9.3

[PATCH v2 06/10] x86/hyper-v: implement rep hypercalls

[Vitaly Kuznetsov]

Rep hypercalls are normal hypercalls which perform multiple actions at
once. Hyper-V guarantees to return exectution to the caller in not more
than 50us and the caller needs to use hypercall continuation. Touch NMI
watchdog between hypercall invocations.

This is going to be used for HvFlushVirtualAddressList hypercall for
remote TLB flushing.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
    - add variable header size
---
 arch/x86/include/asm/mshyperv.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 7b9b404..3a0b3f8 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -4,6 +4,7 @@
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/clocksource.h>
+#include <linux/nmi.h>
 #include <asm/hyperv.h>
 
 /*
@@ -255,6 +256,31 @@ static inline u64 hv_do_fast_hypercall8(u16 code, u64 input1)
 #endif
 }
 
+/*
+ * Rep hypercalls. Callers of this functions are supposed to ensure that
+ * rep_count and vahead_size comply with union hv_hypercall_input definition.
+ */
+static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
+				      void *input, void *output)
+{
+	union hv_hypercall_input hc_input = { .code = code,
+					      .varhead_size = varhead_size,
+					      .rep_count = rep_count};
+	u64 status;
+
+	do {
+		status = hv_do_hypercall(hc_input.as_uint64, input, output);
+		if ((status & 0xffff) != HV_STATUS_SUCCESS)
+			return status;
+
+		hc_input.rep_start = (status >> 32) & 0xfff;
+
+		touch_nmi_watchdog();
+	} while (hc_input.rep_start < hc_input.rep_count);
+
+	return status;
+}
+
 void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
-- 
2.9.3

[PATCH v2 07/10] hyper-v: globalize vp_index

[Vitaly Kuznetsov]

To support implementing remote TLB flushing on Hyper-V with a hypercall
we need to make vp_index available outside of vmbus module. Rename and
globalize.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
- rename vmbus_cpu_number_to_vp_number() -> hv_cpu_number_to_vp_number()
  as we move the function to common code [K. Y. Srinivasan]
---
 arch/x86/hyperv/hv_init.c       | 34 +++++++++++++++++++++++++++++++++-
 arch/x86/include/asm/mshyperv.h | 26 ++++++++++++++++++++++++++
 drivers/hv/channel_mgmt.c       |  7 +++----
 drivers/hv/connection.c         |  3 ++-
 drivers/hv/hv.c                 |  9 ---------
 drivers/hv/hyperv_vmbus.h       | 11 -----------
 drivers/hv/vmbus_drv.c          | 17 -----------------
 drivers/pci/host/pci-hyperv.c   |  4 ++--
 include/linux/hyperv.h          |  1 -
 9 files changed, 66 insertions(+), 46 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 7d961d4..1c14088 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -26,6 +26,8 @@
 #include <linux/mm.h>
 #include <linux/clockchips.h>
 #include <linux/hyperv.h>
+#include <linux/slab.h>
+#include <linux/cpuhotplug.h>
 
 #ifdef CONFIG_X86_64
 
@@ -103,6 +105,20 @@ EXPORT_SYMBOL_GPL(hv_hypercall_pg);
 struct clocksource *hyperv_cs;
 EXPORT_SYMBOL_GPL(hyperv_cs);
 
+u32 *hv_vp_index;
+EXPORT_SYMBOL_GPL(hv_vp_index);
+
+static int hv_cpu_init(unsigned int cpu)
+{
+	u64 msr_vp_index;
+
+	hv_get_vp_index(msr_vp_index);
+
+	hv_vp_index[smp_processor_id()] = (u32)msr_vp_index;
+
+	return 0;
+}
+
 /*
  * This function is to be invoked early in the boot sequence after the
  * hypervisor has been detected.
@@ -118,6 +134,16 @@ void hyperv_init(void)
 	if (x86_hyper != &x86_hyper_ms_hyperv)
 		return;
 
+	/* Allocate percpu VP index */
+	hv_vp_index = kcalloc(num_possible_cpus(), sizeof(*hv_vp_index),
+			      GFP_KERNEL);
+	if (!hv_vp_index)
+		return;
+
+	if (cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online",
+			      hv_cpu_init, NULL) < 0)
+		goto free_vp_index;
+
 	/*
 	 * Setup the hypercall page and enable hypercalls.
 	 * 1. Register the guest ID
@@ -129,7 +155,7 @@ void hyperv_init(void)
 	hv_hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_RX);
 	if (hv_hypercall_pg == NULL) {
 		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
-		return;
+		goto free_vp_index;
 	}
 
 	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
@@ -169,6 +195,12 @@ void hyperv_init(void)
 	hyperv_cs = &hyperv_cs_msr;
 	if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
 		clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
+
+	return;
+
+free_vp_index:
+	kfree(hv_vp_index);
+	hv_vp_index = NULL;
 }
 
 /*
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 3a0b3f8..fd1f101 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -281,6 +281,32 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
 	return status;
 }
 
+/*
+ * Hypervisor's notion of virtual processor ID is different from
+ * Linux' notion of CPU ID. This information can only be retrieved
+ * in the context of the calling CPU. Setup a map for easy access
+ * to this information.
+ */
+extern u32 __percpu *hv_vp_index;
+
+/**
+ * hv_cpu_number_to_vp_number() - Map CPU to VP.
+ * @cpu_number: CPU number in Linux terms
+ *
+ * This function returns the mapping between the Linux processor
+ * number and the hypervisor's virtual processor number, useful
+ * in making hypercalls and such that talk about specific
+ * processors.
+ *
+ * Return: Virtual processor number in Hyper-V terms
+ */
+static inline int hv_cpu_number_to_vp_number(int cpu_number)
+{
+	WARN_ON(hv_vp_index[cpu_number] == -1);
+
+	return hv_vp_index[cpu_number];
+}
+
 void hyperv_init(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 6cfa297..c754446 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -599,7 +599,7 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)
 		 */
 		channel->numa_node = 0;
 		channel->target_cpu = 0;
-		channel->target_vp = hv_context.vp_index[0];
+		channel->target_vp = hv_cpu_number_to_vp_number(0);
 		return;
 	}
 
@@ -683,7 +683,7 @@ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)
 	}
 
 	channel->target_cpu = cur_cpu;
-	channel->target_vp = hv_context.vp_index[cur_cpu];
+	channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu);
 }
 
 static void vmbus_wait_for_unload(void)
@@ -1187,8 +1187,7 @@ struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
 		return outgoing_channel;
 	}
 
-	cur_cpu = hv_context.vp_index[get_cpu()];
-	put_cpu();
+	cur_cpu = hv_cpu_number_to_vp_number(smp_processor_id());
 	list_for_each_safe(cur, tmp, &primary->sc_list) {
 		cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 		if (cur_channel->state != CHANNEL_OPENED_STATE)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 545f2a4..30f2478 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -96,7 +96,8 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	 * the CPU attempting to connect may not be CPU 0.
 	 */
 	if (version >= VERSION_WIN8_1)
-		msg->target_vcpu = hv_context.vp_index[smp_processor_id()];
+		msg->target_vcpu =
+			hv_cpu_number_to_vp_number(smp_processor_id());
 	else
 		msg->target_vcpu = 0;
 
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 12e7bae..7e67ef4 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -229,7 +229,6 @@ int hv_synic_init(unsigned int cpu)
 	union hv_synic_siefp siefp;
 	union hv_synic_sint shared_sint;
 	union hv_synic_scontrol sctrl;
-	u64 vp_index;
 
 	/* Setup the Synic's message page */
 	hv_get_simp(simp.as_uint64);
@@ -271,14 +270,6 @@ int hv_synic_init(unsigned int cpu)
 	hv_context.synic_initialized = true;
 
 	/*
-	 * Setup the mapping between Hyper-V's notion
-	 * of cpuid and Linux' notion of cpuid.
-	 * This array will be indexed using Linux cpuid.
-	 */
-	hv_get_vp_index(vp_index);
-	hv_context.vp_index[cpu] = (u32)vp_index;
-
-	/*
 	 * Register the per-cpu clockevent source.
 	 */
 	if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 6113e91..d624526 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -229,17 +229,6 @@ struct hv_context {
 	struct hv_per_cpu_context __percpu *cpu_context;
 
 	/*
-	 * Hypervisor's notion of virtual processor ID is different from
-	 * Linux' notion of CPU ID. This information can only be retrieved
-	 * in the context of the calling CPU. Setup a map for easy access
-	 * to this information:
-	 *
-	 * vp_index[a] is the Hyper-V's processor ID corresponding to
-	 * Linux cpuid 'a'.
-	 */
-	u32 vp_index[NR_CPUS];
-
-	/*
 	 * To manage allocations in a NUMA node.
 	 * Array indexed by numa node ID.
 	 */
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 0087b49..63e743d 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1455,23 +1455,6 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
 }
 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
 
-/**
- * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
- * @cpu_number: CPU number in Linux terms
- *
- * This function returns the mapping between the Linux processor
- * number and the hypervisor's virtual processor number, useful
- * in making hypercalls and such that talk about specific
- * processors.
- *
- * Return: Virtual processor number in Hyper-V terms
- */
-int vmbus_cpu_number_to_vp_number(int cpu_number)
-{
-	return hv_context.vp_index[cpu_number];
-}
-EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
-
 static int vmbus_acpi_add(struct acpi_device *device)
 {
 	acpi_status result;
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index ada9856..7cdd66e 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -807,7 +807,7 @@ static void hv_irq_unmask(struct irq_data *data)
 	params->vector = cfg->vector;
 
 	for_each_cpu_and(cpu, dest, cpu_online_mask)
-		params->vp_mask |= (1ULL << vmbus_cpu_number_to_vp_number(cpu));
+		params->vp_mask |= (1ULL << hv_cpu_number_to_vp_number(cpu));
 
 	hv_do_hypercall(HVCALL_RETARGET_INTERRUPT, params, NULL);
 
@@ -899,7 +899,7 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
 	affinity = irq_data_get_affinity_mask(data);
 	for_each_cpu_and(cpu, affinity, cpu_online_mask) {
 		int_pkt->int_desc.cpu_mask |=
-			(1ULL << vmbus_cpu_number_to_vp_number(cpu));
+			(1ULL << hv_cpu_number_to_vp_number(cpu));
 	}
 
 	ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt,
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 5d6777c..2450e07 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1184,7 +1184,6 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 			resource_size_t size, resource_size_t align,
 			bool fb_overlap_ok);
 void vmbus_free_mmio(resource_size_t start, resource_size_t size);
-int vmbus_cpu_number_to_vp_number(int cpu_number);
 
 /*
  * GUID definitions of various offer types - services offered to the guest.
-- 
2.9.3

[PATCH v2 08/10] x86/hyper-v: use hypercall for remote TLB flush

[Vitaly Kuznetsov]

Hyper-V host can suggest us to use hypercall for doing remote TLB flush,
this is supposed to work faster than IPIs.

Implementation details: to do HvFlushVirtualAddress{Space,List} hypercalls
we need to put the input somewhere in memory and we don't really want to
have memory allocation on each call so we pre-allocate per cpu memory areas
on boot. These areas are of fixes size, limit them with an arbitrary number
of 16 (16 gvas are able to specify 16 * 4096 pages).

pv_ops patching is happening very early so we need to separate
hyperv_setup_mmu_ops() and hyper_alloc_mmu().

It is possible and easy to implement local TLB flushing too and there is
even a hint for that. However, I don't see a room for optimization on the
host side as both hypercall and native tlb flush will result in vmexit. The
hint is also not set on modern Hyper-V versions.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
- Use local_irq_save/restore instead of spinlock [Jork Loeser].
- Make sure struct hv_flush_pcpu doesn't cross page boundary [Jork Loeser].
- mm can be NULL, account for that [Simon Xiao]
---
 arch/x86/hyperv/Makefile           |   2 +-
 arch/x86/hyperv/hv_init.c          |   2 +
 arch/x86/hyperv/mmu.c              | 117 +++++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/mshyperv.h    |   3 +
 arch/x86/include/uapi/asm/hyperv.h |   7 +++
 arch/x86/kernel/cpu/mshyperv.c     |   1 +
 6 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 arch/x86/hyperv/mmu.c

diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
index 171ae09..367a820 100644
--- a/arch/x86/hyperv/Makefile
+++ b/arch/x86/hyperv/Makefile
@@ -1 +1 @@
-obj-y		:= hv_init.o
+obj-y		:= hv_init.o mmu.o
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 1c14088..2cf8a98 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -163,6 +163,8 @@ void hyperv_init(void)
 	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
+	hyper_alloc_mmu();
+
 	/*
 	 * Register Hyper-V specific clocksource.
 	 */
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
new file mode 100644
index 0000000..e3ab9b9
--- /dev/null
+++ b/arch/x86/hyperv/mmu.c
@@ -0,0 +1,117 @@
+#include <linux/types.h>
+#include <linux/hyperv.h>
+#include <linux/slab.h>
+#include <linux/log2.h>
+#include <asm/mshyperv.h>
+#include <asm/tlbflush.h>
+#include <asm/msr.h>
+#include <asm/fpu/api.h>
+
+/* HvFlushVirtualAddressSpace, HvFlushVirtualAddressList hypercalls */
+struct hv_flush_pcpu {
+	__u64 address_space;
+	__u64 flags;
+	__u64 processor_mask;
+	__u64 gva_list[];
+};
+
+static struct hv_flush_pcpu __percpu *pcpu_flush;
+
+static void hyperv_flush_tlb_others(const struct cpumask *cpus,
+				    struct mm_struct *mm, unsigned long start,
+				    unsigned long end)
+{
+	struct hv_flush_pcpu *flush;
+	unsigned long cur, flags;
+	u64 status = -1ULL;
+	int cpu, vcpu, gva_n, max_gvas;
+
+	if (!pcpu_flush || !hv_hypercall_pg)
+		goto do_native;
+
+	if (cpumask_empty(cpus))
+		return;
+
+	local_irq_save(flags);
+
+	flush = this_cpu_ptr(pcpu_flush);
+
+	if (mm) {
+		flush->address_space = virt_to_phys(mm->pgd);
+		flush->flags = 0;
+	} else {
+		flush->address_space = 0;
+		flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
+	}
+
+	flush->processor_mask = 0;
+	if (cpumask_equal(cpus, cpu_present_mask)) {
+		flush->flags |= HV_FLUSH_ALL_PROCESSORS;
+	} else {
+		for_each_cpu(cpu, cpus) {
+			vcpu = hv_cpu_number_to_vp_number(cpu);
+			if (vcpu != -1 && vcpu < 64)
+				flush->processor_mask |= 1 << vcpu;
+			else
+				goto do_native;
+		}
+	}
+
+	/*
+	 * We can flush not more than max_gvas with one hypercall. Flush the
+	 * whole address space if we were asked to do more.
+	 */
+	max_gvas = (PAGE_SIZE - sizeof(*flush)) / 8;
+
+	if (end == TLB_FLUSH_ALL ||
+	    (end && ((end - start)/(PAGE_SIZE*PAGE_SIZE)) > max_gvas)) {
+		if (end == TLB_FLUSH_ALL)
+			flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
+		status = hv_do_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE,
+					 flush, NULL);
+	} else {
+		cur = start;
+		gva_n = 0;
+		do {
+			flush->gva_list[gva_n] = cur & PAGE_MASK;
+			/*
+			 * Lower 12 bits encode the number of additional
+			 * pages to flush (in addition to the 'cur' page).
+			 */
+			if (end >= cur + PAGE_SIZE * PAGE_SIZE)
+				flush->gva_list[gva_n] |= ~PAGE_MASK;
+			else if (end > cur)
+				flush->gva_list[gva_n] |=
+					(end - cur - 1) >> PAGE_SHIFT;
+
+			cur += PAGE_SIZE * PAGE_SIZE;
+			++gva_n;
+
+		} while (cur < end);
+
+		status = hv_do_rep_hypercall(HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST,
+					     gva_n, 0, flush, NULL);
+
+	}
+
+	local_irq_restore(flags);
+
+	if (!(status & 0xffff))
+		return;
+do_native:
+	native_flush_tlb_others(cpus, mm, start, end);
+}
+
+void hyperv_setup_mmu_ops(void)
+{
+	if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED) {
+		pr_info("Hyper-V: Using hypercall for remote TLB flush\n");
+		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
+	}
+}
+
+void hyper_alloc_mmu(void)
+{
+	if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)
+		pcpu_flush = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
+}
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index fd1f101..bb65f53 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -308,6 +308,8 @@ static inline int hv_cpu_number_to_vp_number(int cpu_number)
 }
 
 void hyperv_init(void);
+void hyperv_setup_mmu_ops(void);
+void hyper_alloc_mmu(void);
 void hyperv_report_panic(struct pt_regs *regs);
 bool hv_is_hypercall_page_setup(void);
 void hyperv_cleanup(void);
@@ -318,5 +320,6 @@ static inline bool hv_is_hypercall_page_setup(void)
 	return false;
 }
 static inline hyperv_cleanup(void) {}
+static inline void hyperv_setup_mmu_ops(void) {}
 #endif /* CONFIG_HYPERV */
 #endif
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index c87e900..3d44036 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -239,6 +239,8 @@
 		(~((1ull << HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT) - 1))
 
 /* Declare the various hypercall operations. */
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE	0x0002
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST	0x0003
 #define HVCALL_NOTIFY_LONG_SPIN_WAIT		0x0008
 #define HVCALL_POST_MESSAGE			0x005c
 #define HVCALL_SIGNAL_EVENT			0x005d
@@ -256,6 +258,11 @@
 #define HV_PROCESSOR_POWER_STATE_C2		2
 #define HV_PROCESSOR_POWER_STATE_C3		3
 
+#define HV_FLUSH_ALL_PROCESSORS			0x00000001
+#define HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES	0x00000002
+#define HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY	0x00000004
+#define HV_FLUSH_USE_EXTENDED_RANGE_FORMAT	0x00000008
+
 /* Hypercall interface */
 union hv_hypercall_input {
 	u64 as_uint64;
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index a8b4765..16a9221 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -240,6 +240,7 @@ static void __init ms_hyperv_init_platform(void)
 	 * Setup the hook to get control post apic initialization.
 	 */
 	x86_platform.apic_post_init = hyperv_init;
+	hyperv_setup_mmu_ops();
 #endif
 }
 
-- 
2.9.3

[PATCH v2 09/10] x86/hyper-v: support extended CPU ranges for TLB flush hypercalls

[Vitaly Kuznetsov]

Hyper-V hosts may support more than 64 vCPUs, we need to use
HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX hypercalls in this
case.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 arch/x86/hyperv/mmu.c              | 149 ++++++++++++++++++++++++++++++++++++-
 arch/x86/include/uapi/asm/hyperv.h |  10 +++
 2 files changed, 157 insertions(+), 2 deletions(-)

diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index e3ab9b9..c9cecb3 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -15,8 +15,57 @@ struct hv_flush_pcpu {
 	__u64 gva_list[];
 };
 
+/* HvFlushVirtualAddressSpaceEx, HvFlushVirtualAddressListEx hypercalls */
+struct hv_flush_pcpu_ex {
+	__u64 address_space;
+	__u64 flags;
+	struct {
+		__u64 format;
+		__u64 valid_bank_mask;
+		__u64 bank_contents[];
+	} hv_vp_set;
+	__u64 gva_list[];
+};
+
 static struct hv_flush_pcpu __percpu *pcpu_flush;
 
+static struct hv_flush_pcpu_ex __percpu *pcpu_flush_ex;
+
+static inline int cpumask_to_vp_set(struct hv_flush_pcpu_ex *flush,
+				    const struct cpumask *cpus)
+{
+	int cur_bank, cpu, vcpu, nr_bank = 0;
+	bool has_cpus;
+
+	/*
+	 * We can't be sure that translated vcpu numbers will always be
+	 * in ascending order, so iterate over all possible banks and
+	 * check all vcpus in it instead.
+	 */
+	for (cur_bank = 0; cur_bank < ms_hyperv.max_vp_index/64; cur_bank++) {
+		has_cpus = false;
+		for_each_cpu(cpu, cpus) {
+			vcpu = hv_cpu_number_to_vp_number(cpu);
+			if (vcpu/64 != cur_bank)
+				continue;
+			if (!has_cpus) {
+				flush->hv_vp_set.valid_bank_mask |=
+					1 << vcpu / 64;
+				flush->hv_vp_set.bank_contents[nr_bank] =
+					1 << vcpu % 64;
+				has_cpus = true;
+			} else {
+				flush->hv_vp_set.bank_contents[nr_bank] |=
+					1 << vcpu % 64;
+			}
+		}
+		if (has_cpus)
+			nr_bank++;
+	}
+
+	return nr_bank;
+}
+
 static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 				    struct mm_struct *mm, unsigned long start,
 				    unsigned long end)
@@ -102,16 +151,112 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 	native_flush_tlb_others(cpus, mm, start, end);
 }
 
+static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
+				       struct mm_struct *mm,
+				       unsigned long start,
+				       unsigned long end)
+{
+	struct hv_flush_pcpu_ex *flush;
+	unsigned long cur, flags;
+	u64 status = -1ULL;
+	int nr_bank = 0, max_gvas, gva_n;
+
+	if (!pcpu_flush_ex || !hv_hypercall_pg)
+		goto do_native;
+
+	if (cpumask_empty(cpus))
+		return;
+
+	local_irq_save(flags);
+
+	flush = this_cpu_ptr(pcpu_flush_ex);
+
+	if (mm) {
+		flush->address_space = virt_to_phys(mm->pgd);
+		flush->flags = 0;
+	} else {
+		flush->address_space = 0;
+		flush->flags = HV_FLUSH_ALL_VIRTUAL_ADDRESS_SPACES;
+	}
+
+	flush->hv_vp_set.valid_bank_mask = 0;
+
+	if (cpumask_equal(cpus, cpu_present_mask)) {
+		flush->hv_vp_set.format = HV_GENERIC_SET_ALL;
+		flush->flags |= HV_FLUSH_ALL_PROCESSORS;
+	} else {
+		flush->hv_vp_set.format = HV_GENERIC_SET_SPARCE_4K;
+		nr_bank = cpumask_to_vp_set(flush, cpus);
+	}
+
+	/*
+	 * We can flush not more than max_gvas with one hypercall. Flush the
+	 * whole address space if we were asked to do more.
+	 */
+	max_gvas = (PAGE_SIZE - sizeof(*flush) - nr_bank*8) / 8;
+
+	if (end == TLB_FLUSH_ALL ||
+	    (end && ((end - start)/(PAGE_SIZE*PAGE_SIZE)) > max_gvas)) {
+		if (end == TLB_FLUSH_ALL)
+			flush->flags |= HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY;
+
+		status = hv_do_rep_hypercall(
+			HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX,
+			0, nr_bank + 2, flush, NULL);
+	} else {
+		cur = start;
+		gva_n = nr_bank;
+		do {
+			flush->gva_list[gva_n] = cur & PAGE_MASK;
+			/*
+			 * Lower 12 bits encode the number of additional
+			 * pages to flush (in addition to the 'cur' page).
+			 */
+			if (end >= cur + PAGE_SIZE * PAGE_SIZE)
+				flush->gva_list[gva_n] |= ~PAGE_MASK;
+			else if (end > cur)
+				flush->gva_list[gva_n] |=
+					(end - cur - 1) >> PAGE_SHIFT;
+
+			cur += PAGE_SIZE * PAGE_SIZE;
+			++gva_n;
+
+		} while (cur < end);
+
+		status = hv_do_rep_hypercall(
+			HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX,
+			gva_n, nr_bank + 2, flush, NULL);
+	}
+
+	local_irq_restore(flags);
+
+	if (!(status & 0xffff))
+		return;
+do_native:
+	native_flush_tlb_others(cpus, mm, start, end);
+}
+
 void hyperv_setup_mmu_ops(void)
 {
-	if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED) {
+	if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
+		return;
+
+	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED)) {
 		pr_info("Hyper-V: Using hypercall for remote TLB flush\n");
 		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others;
+	} else {
+		pr_info("Hyper-V: Using ext hypercall for remote TLB flush\n");
+		pv_mmu_ops.flush_tlb_others = hyperv_flush_tlb_others_ex;
 	}
 }
 
 void hyper_alloc_mmu(void)
 {
-	if (ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED)
+	if (!(ms_hyperv.hints & HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED))
+		return;
+
+	if (!(ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED))
 		pcpu_flush = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
+	else
+		pcpu_flush_ex = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
 }
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 3d44036..c697e20 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -152,6 +152,9 @@
  */
 #define HV_X64_DEPRECATING_AEOI_RECOMMENDED	(1 << 9)
 
+/* Recommend using the newer ExProcessorMasks interface */
+#define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED	(1 << 11)
+
 /*
  * Crash notification flag.
  */
@@ -242,6 +245,8 @@
 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE	0x0002
 #define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST	0x0003
 #define HVCALL_NOTIFY_LONG_SPIN_WAIT		0x0008
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX  0x0013
+#define HVCALL_FLUSH_VIRTUAL_ADDRESS_LIST_EX   0x0014
 #define HVCALL_POST_MESSAGE			0x005c
 #define HVCALL_SIGNAL_EVENT			0x005d
 
@@ -263,6 +268,11 @@
 #define HV_FLUSH_NON_GLOBAL_MAPPINGS_ONLY	0x00000004
 #define HV_FLUSH_USE_EXTENDED_RANGE_FORMAT	0x00000008
 
+enum HV_GENERIC_SET_FORMAT {
+	HV_GENERIC_SET_SPARCE_4K,
+	HV_GENERIC_SET_ALL,
+};
+
 /* Hypercall interface */
 union hv_hypercall_input {
 	u64 as_uint64;
-- 
2.9.3

[PATCH v2 10/10] tracing/hyper-v: trace hyperv_mmu_flush_tlb_others()

[Vitaly Kuznetsov]

Add Hyper-V tracing subsystem and trace hyperv_mmu_flush_tlb_others().
Tracing is done the same way we do xen_mmu_flush_tlb_others().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
Changes since v1:
- Move hyperv.h to arch-specific place (Steven Rostedt)
- Add IS_ENABLED(CONFIG_HYPERV) to hyperv.h
---
 MAINTAINERS                         |  1 +
 arch/x86/hyperv/mmu.c               |  8 ++++++++
 arch/x86/include/asm/trace/hyperv.h | 34 ++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)
 create mode 100644 arch/x86/include/asm/trace/hyperv.h

diff --git a/MAINTAINERS b/MAINTAINERS
index ef0d61c..c10c4ee 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6047,6 +6047,7 @@ M:	Stephen Hemminger <sthemmin@microsoft.com>
 L:	devel@linuxdriverproject.org
 S:	Maintained
 F:	arch/x86/include/asm/mshyperv.h
+F:	arch/x86/include/asm/trace/hyperv.h
 F:	arch/x86/include/uapi/asm/hyperv.h
 F:	arch/x86/kernel/cpu/mshyperv.c
 F:	arch/x86/hyperv
diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c
index c9cecb3..f6b5211 100644
--- a/arch/x86/hyperv/mmu.c
+++ b/arch/x86/hyperv/mmu.c
@@ -6,6 +6,10 @@
 #include <asm/tlbflush.h>
 #include <asm/msr.h>
 #include <asm/fpu/api.h>
+#include <asm/trace/hyperv.h>
+
+#define CREATE_TRACE_POINTS
+DEFINE_TRACE(hyperv_mmu_flush_tlb_others);
 
 /* HvFlushVirtualAddressSpace, HvFlushVirtualAddressList hypercalls */
 struct hv_flush_pcpu {
@@ -75,6 +79,8 @@ static void hyperv_flush_tlb_others(const struct cpumask *cpus,
 	u64 status = -1ULL;
 	int cpu, vcpu, gva_n, max_gvas;
 
+	trace_hyperv_mmu_flush_tlb_others(cpus, mm, start, end);
+
 	if (!pcpu_flush || !hv_hypercall_pg)
 		goto do_native;
 
@@ -161,6 +167,8 @@ static void hyperv_flush_tlb_others_ex(const struct cpumask *cpus,
 	u64 status = -1ULL;
 	int nr_bank = 0, max_gvas, gva_n;
 
+	trace_hyperv_mmu_flush_tlb_others(cpus, mm, start, end);
+
 	if (!pcpu_flush_ex || !hv_hypercall_pg)
 		goto do_native;
 
diff --git a/arch/x86/include/asm/trace/hyperv.h b/arch/x86/include/asm/trace/hyperv.h
new file mode 100644
index 0000000..e46a351
--- /dev/null
+++ b/arch/x86/include/asm/trace/hyperv.h
@@ -0,0 +1,34 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM hyperv
+
+#if !defined(_TRACE_HYPERV_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HYPERV_H
+
+#include <linux/tracepoint.h>
+
+#if IS_ENABLED(CONFIG_HYPERV)
+
+TRACE_EVENT(hyperv_mmu_flush_tlb_others,
+	    TP_PROTO(const struct cpumask *cpus, struct mm_struct *mm,
+		     unsigned long addr, unsigned long end),
+	    TP_ARGS(cpus, mm, addr, end),
+	    TP_STRUCT__entry(
+		    __field(unsigned int, ncpus)
+		    __field(struct mm_struct *, mm)
+		    __field(unsigned long, addr)
+		    __field(unsigned long, end)
+		    ),
+	    TP_fast_assign(__entry->ncpus = cpumask_weight(cpus);
+			   __entry->mm = mm;
+			   __entry->addr = addr,
+			   __entry->end = end),
+	    TP_printk("ncpus %d mm %p addr %lx, end %lx",
+		      __entry->ncpus, __entry->mm, __entry->addr, __entry->end)
+	);
+
+#endif /* CONFIG_HYPERV */
+
+#endif /* _TRACE_HYPERV_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.9.3

RE: [PATCH v2 00/10] Hyper-V: praravirtualized remote TLB flushing and hypercall improvements

[KY Srinivasan]

> -----Original Message-----
> From: Vitaly Kuznetsov [mailto:vkuznets@redhat.com]
> Sent: Wednesday, April 12, 2017 3:43 AM
> To: devel@linuxdriverproject.org; x86@kernel.org
> Cc: linux-kernel@vger.kernel.org; KY Srinivasan <kys@microsoft.com>;
> Haiyang Zhang <haiyangz@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Thomas Gleixner <tglx@linutronix.de>; Ingo
> Molnar <mingo@redhat.com>; H. Peter Anvin <hpa@zytor.com>; Steven
> Rostedt <rostedt@goodmis.org>; Jork Loeser
> <Jork.Loeser@microsoft.com>; Simon Xiao <sixiao@microsoft.com>
> Subject: [PATCH v2 00/10] Hyper-V: praravirtualized remote TLB flushing and
> hypercall improvements
> 
> Changes since v1:
> - Add a patch to build code in arch/x86/hyperv/ only when CONFIG_HYPERV
> is
>   set.
> - Add a patch to get maximum virtual/logical processor on Hyper-V.
> - Add additional clobbers to hypercalls [Jork Loeser]
> - Add variable header size support to rep hypercalls.
> - Rename vmbus_cpu_number_to_vp_number ->
> hv_cpu_number_to_vp_number
>   [K. Y. Srinivasan]
> - Remove spinlocks from hyperv_flush_tlb_others() [Jork Loeser]
> - Account for mm==NULL in hyperv_flush_tlb_others() [Simon Xiao]
> - Add support for HVCALL_FLUSH_VIRTUAL_ADDRESS_SPACE_EX/LIST_EX
> hypercalls
>   to support >64 vCPUs [K. Y. Srinivasan, Jork Loeser]
> - Move hyperv.h to arch-specific place [Steven Rostedt]
> - Rebased to the latest char-misc-next tree.
> 
> Original descriptions:
> 
> Hyper-V supports hypercalls for doing local and remote TLB flushing and
> gives its guests hints when using hypercall is preferred. While doing
> hypercalls for local TLB flushes is probably not practical (and is not
> being suggested by modern Hyper-V versions) remote TLB flush with a
> hypercall brings significant improvement.
> 
> To test the series I wrote a special 'TLB trasher': on a 16 vCPU guest I
> was creating 32 threads which were doing 100000 mmap/munmaps each on
> some
> big file. Here are the results:
> 
> Before:
> # time ./pthread_mmap ./randfile
> real	3m44.994s
> user	0m3.829s
> sys	3m36.323s
> 
> After:
> # time ./pthread_mmap ./randfile
> real	2m57.145s
> user	0m3.797s
> sys	2m34.812s
> 
> This series brings a number of small improvements along the way: fast
> hypercall implementation and using it for event signaling, rep hypercalls
> implementation, hyperv tracing subsystem (which only traces the newly
> added
> remote TLB flush for now).
> 
> Vitaly Kuznetsov (10):
>   x86/hyper-v: include hyperv/ only when CONFIG_HYPERV is set
>   x86/hyper-v: stash the max number of virtual/logical processor
>   x86/hyper-v: make hv_do_hypercall() inline
>   x86/hyper-v: fast hypercall implementation
>   hyper-v: use fast hypercall for HVCALL_SIGNAL_EVENT
>   x86/hyper-v: implement rep hypercalls
>   hyper-v: globalize vp_index
>   x86/hyper-v: use hypercall for remote TLB flush
>   x86/hyper-v: support extended CPU ranges for TLB flush hypercalls
>   tracing/hyper-v: trace hyperv_mmu_flush_tlb_others()

Thanks Vitaly; we have tested these patches on various platforms of interest.

Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Simon Xiao <sixiao@microsoft.com>
Tested-by: Srikanth Myakam <v-srm@microsoft.com>

Regards,

K. Y
> 
>  MAINTAINERS                         |   1 +
>  arch/x86/Kbuild                     |   4 +-
>  arch/x86/hyperv/Makefile            |   2 +-
>  arch/x86/hyperv/hv_init.c           |  90 ++++++------
>  arch/x86/hyperv/mmu.c               | 270
> ++++++++++++++++++++++++++++++++++++
>  arch/x86/include/asm/mshyperv.h     | 148 +++++++++++++++++++-
>  arch/x86/include/asm/trace/hyperv.h |  34 +++++
>  arch/x86/include/uapi/asm/hyperv.h  |  36 +++++
>  arch/x86/kernel/cpu/mshyperv.c      |  14 +-
>  drivers/hv/channel_mgmt.c           |  22 ++-
>  drivers/hv/connection.c             |   8 +-
>  drivers/hv/hv.c                     |   9 --
>  drivers/hv/hyperv_vmbus.h           |  11 --
>  drivers/hv/vmbus_drv.c              |  17 ---
>  drivers/pci/host/pci-hyperv.c       |   4 +-
>  include/linux/hyperv.h              |  21 ++-
>  16 files changed, 567 insertions(+), 124 deletions(-)
>  create mode 100644 arch/x86/hyperv/mmu.c
>  create mode 100644 arch/x86/include/asm/trace/hyperv.h
> 
> --
> 2.9.3