From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>,
"George Dunlap" <george.dunlap@citrix.com>,
"Tim Deegan" <tim@xen.org>
Subject: [PATCH v2 11/12] x86/p2m: write_p2m_entry_{pre,post} hooks are HVM-only
Date: Mon, 12 Apr 2021 16:13:52 +0200 [thread overview]
Message-ID: <507182a8-38c3-cda3-d921-7494a5df63a7@suse.com> (raw)
In-Reply-To: <3cf73378-b9d6-0eca-12b6-0f628518bebf@suse.com>
Move respective shadow code to its HVM-only source file, thus making it
possible to exclude the hooks as well. This then shows that
shadow_p2m_init() also isn't needed in !HVM builds.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
v2: New.
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -2327,22 +2327,6 @@ void shadow_prepare_page_type_change(str
shadow_remove_all_shadows(d, page_to_mfn(page));
}
-static void
-sh_remove_all_shadows_and_parents(struct domain *d, mfn_t gmfn)
-/* Even harsher: this is a HVM page that we thing is no longer a pagetable.
- * Unshadow it, and recursively unshadow pages that reference it. */
-{
- sh_remove_shadows(d, gmfn, 0, 1);
- /* XXX TODO:
- * Rework this hashtable walker to return a linked-list of all
- * the shadows it modified, then do breadth-first recursion
- * to find the way up to higher-level tables and unshadow them too.
- *
- * The current code (just tearing down each page's shadows as we
- * detect that it is not a pagetable) is correct, but very slow.
- * It means extra emulated writes and slows down removal of mappings. */
-}
-
/**************************************************************************/
/* Reset the up-pointers of every L3 shadow to 0.
@@ -3086,126 +3070,6 @@ static int shadow_test_disable(struct do
}
/**************************************************************************/
-/* P2M map manipulations */
-
-/* shadow specific code which should be called when P2M table entry is updated
- * with new content. It is responsible for update the entry, as well as other
- * shadow processing jobs.
- */
-
-static void sh_unshadow_for_p2m_change(struct domain *d, unsigned long gfn,
- l1_pgentry_t old, l1_pgentry_t new,
- unsigned int level)
-{
- mfn_t omfn = l1e_get_mfn(old);
- unsigned int oflags = l1e_get_flags(old);
- p2m_type_t p2mt = p2m_flags_to_type(oflags);
- bool flush = false;
-
- /*
- * If there are any shadows, update them. But if shadow_teardown()
- * has already been called then it's not safe to try.
- */
- if ( unlikely(!d->arch.paging.shadow.total_pages) )
- return;
-
- switch ( level )
- {
- default:
- /*
- * The following assertion is to make sure we don't step on 1GB host
- * page support of HVM guest.
- */
- ASSERT(!((oflags & _PAGE_PRESENT) && (oflags & _PAGE_PSE)));
- break;
-
- /* If we're removing an MFN from the p2m, remove it from the shadows too */
- case 1:
- if ( (p2m_is_valid(p2mt) || p2m_is_grant(p2mt)) && mfn_valid(omfn) )
- {
- sh_remove_all_shadows_and_parents(d, omfn);
- if ( sh_remove_all_mappings(d, omfn, _gfn(gfn)) )
- flush = true;
- }
- break;
-
- /*
- * If we're removing a superpage mapping from the p2m, we need to check
- * all the pages covered by it. If they're still there in the new
- * scheme, that's OK, but otherwise they must be unshadowed.
- */
- case 2:
- if ( !(oflags & _PAGE_PRESENT) || !(oflags & _PAGE_PSE) )
- break;
-
- if ( p2m_is_valid(p2mt) && mfn_valid(omfn) )
- {
- unsigned int i;
- mfn_t nmfn = l1e_get_mfn(new);
- l1_pgentry_t *npte = NULL;
-
- /* If we're replacing a superpage with a normal L1 page, map it */
- if ( (l1e_get_flags(new) & _PAGE_PRESENT) &&
- !(l1e_get_flags(new) & _PAGE_PSE) &&
- mfn_valid(nmfn) )
- npte = map_domain_page(nmfn);
-
- gfn &= ~(L1_PAGETABLE_ENTRIES - 1);
-
- for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
- {
- if ( !npte ||
- !p2m_is_ram(p2m_flags_to_type(l1e_get_flags(npte[i]))) ||
- !mfn_eq(l1e_get_mfn(npte[i]), omfn) )
- {
- /* This GFN->MFN mapping has gone away */
- sh_remove_all_shadows_and_parents(d, omfn);
- if ( sh_remove_all_mappings(d, omfn, _gfn(gfn + i)) )
- flush = true;
- }
- omfn = mfn_add(omfn, 1);
- }
-
- if ( npte )
- unmap_domain_page(npte);
- }
-
- break;
- }
-
- if ( flush )
- guest_flush_tlb_mask(d, d->dirty_cpumask);
-}
-
-#if (SHADOW_OPTIMIZATIONS & SHOPT_FAST_FAULT_PATH)
-static void
-sh_write_p2m_entry_post(struct p2m_domain *p2m, unsigned int oflags)
-{
- struct domain *d = p2m->domain;
-
- /* If we're doing FAST_FAULT_PATH, then shadow mode may have
- cached the fact that this is an mmio region in the shadow
- page tables. Blow the tables away to remove the cache.
- This is pretty heavy handed, but this is a rare operation
- (it might happen a dozen times during boot and then never
- again), so it doesn't matter too much. */
- if ( d->arch.paging.shadow.has_fast_mmio_entries )
- {
- shadow_blow_tables(d);
- d->arch.paging.shadow.has_fast_mmio_entries = false;
- }
-}
-#else
-# define sh_write_p2m_entry_post NULL
-#endif
-
-void shadow_p2m_init(struct p2m_domain *p2m)
-{
- p2m->write_p2m_entry_pre = sh_unshadow_for_p2m_change;
- p2m->write_p2m_entry_post = sh_write_p2m_entry_post;
-}
-
-/**************************************************************************/
/* Log-dirty mode support */
/* Shadow specific code which is called in paging_log_dirty_enable().
--- a/xen/arch/x86/mm/shadow/hvm.c
+++ b/xen/arch/x86/mm/shadow/hvm.c
@@ -774,6 +774,142 @@ void sh_destroy_monitor_table(const stru
}
/**************************************************************************/
+/* P2M map manipulations */
+
+/* shadow specific code which should be called when P2M table entry is updated
+ * with new content. It is responsible for update the entry, as well as other
+ * shadow processing jobs.
+ */
+
+static void
+sh_remove_all_shadows_and_parents(struct domain *d, mfn_t gmfn)
+/* Even harsher: this is a HVM page that we thing is no longer a pagetable.
+ * Unshadow it, and recursively unshadow pages that reference it. */
+{
+ sh_remove_shadows(d, gmfn, 0, 1);
+ /* XXX TODO:
+ * Rework this hashtable walker to return a linked-list of all
+ * the shadows it modified, then do breadth-first recursion
+ * to find the way up to higher-level tables and unshadow them too.
+ *
+ * The current code (just tearing down each page's shadows as we
+ * detect that it is not a pagetable) is correct, but very slow.
+ * It means extra emulated writes and slows down removal of mappings. */
+}
+
+static void sh_unshadow_for_p2m_change(struct domain *d, unsigned long gfn,
+ l1_pgentry_t old, l1_pgentry_t new,
+ unsigned int level)
+{
+ mfn_t omfn = l1e_get_mfn(old);
+ unsigned int oflags = l1e_get_flags(old);
+ p2m_type_t p2mt = p2m_flags_to_type(oflags);
+ bool flush = false;
+
+ /*
+ * If there are any shadows, update them. But if shadow_teardown()
+ * has already been called then it's not safe to try.
+ */
+ if ( unlikely(!d->arch.paging.shadow.total_pages) )
+ return;
+
+ switch ( level )
+ {
+ default:
+ /*
+ * The following assertion is to make sure we don't step on 1GB host
+ * page support of HVM guest.
+ */
+ ASSERT(!((oflags & _PAGE_PRESENT) && (oflags & _PAGE_PSE)));
+ break;
+
+ /* If we're removing an MFN from the p2m, remove it from the shadows too */
+ case 1:
+ if ( (p2m_is_valid(p2mt) || p2m_is_grant(p2mt)) && mfn_valid(omfn) )
+ {
+ sh_remove_all_shadows_and_parents(d, omfn);
+ if ( sh_remove_all_mappings(d, omfn, _gfn(gfn)) )
+ flush = true;
+ }
+ break;
+
+ /*
+ * If we're removing a superpage mapping from the p2m, we need to check
+ * all the pages covered by it. If they're still there in the new
+ * scheme, that's OK, but otherwise they must be unshadowed.
+ */
+ case 2:
+ if ( !(oflags & _PAGE_PRESENT) || !(oflags & _PAGE_PSE) )
+ break;
+
+ if ( p2m_is_valid(p2mt) && mfn_valid(omfn) )
+ {
+ unsigned int i;
+ mfn_t nmfn = l1e_get_mfn(new);
+ l1_pgentry_t *npte = NULL;
+
+ /* If we're replacing a superpage with a normal L1 page, map it */
+ if ( (l1e_get_flags(new) & _PAGE_PRESENT) &&
+ !(l1e_get_flags(new) & _PAGE_PSE) &&
+ mfn_valid(nmfn) )
+ npte = map_domain_page(nmfn);
+
+ gfn &= ~(L1_PAGETABLE_ENTRIES - 1);
+
+ for ( i = 0; i < L1_PAGETABLE_ENTRIES; i++ )
+ {
+ if ( !npte ||
+ !p2m_is_ram(p2m_flags_to_type(l1e_get_flags(npte[i]))) ||
+ !mfn_eq(l1e_get_mfn(npte[i]), omfn) )
+ {
+ /* This GFN->MFN mapping has gone away */
+ sh_remove_all_shadows_and_parents(d, omfn);
+ if ( sh_remove_all_mappings(d, omfn, _gfn(gfn + i)) )
+ flush = true;
+ }
+ omfn = mfn_add(omfn, 1);
+ }
+
+ if ( npte )
+ unmap_domain_page(npte);
+ }
+
+ break;
+ }
+
+ if ( flush )
+ guest_flush_tlb_mask(d, d->dirty_cpumask);
+}
+
+#if (SHADOW_OPTIMIZATIONS & SHOPT_FAST_FAULT_PATH)
+static void
+sh_write_p2m_entry_post(struct p2m_domain *p2m, unsigned int oflags)
+{
+ struct domain *d = p2m->domain;
+
+ /* If we're doing FAST_FAULT_PATH, then shadow mode may have
+ cached the fact that this is an mmio region in the shadow
+ page tables. Blow the tables away to remove the cache.
+ This is pretty heavy handed, but this is a rare operation
+ (it might happen a dozen times during boot and then never
+ again), so it doesn't matter too much. */
+ if ( d->arch.paging.shadow.has_fast_mmio_entries )
+ {
+ shadow_blow_tables(d);
+ d->arch.paging.shadow.has_fast_mmio_entries = false;
+ }
+}
+#else
+# define sh_write_p2m_entry_post NULL
+#endif
+
+void shadow_p2m_init(struct p2m_domain *p2m)
+{
+ p2m->write_p2m_entry_pre = sh_unshadow_for_p2m_change;
+ p2m->write_p2m_entry_post = sh_write_p2m_entry_post;
+}
+
+/**************************************************************************/
/* VRAM dirty tracking support */
int shadow_track_dirty_vram(struct domain *d,
unsigned long begin_pfn,
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -278,7 +278,6 @@ struct p2m_domain {
unsigned long first_gfn,
unsigned long last_gfn);
void (*memory_type_changed)(struct p2m_domain *p2m);
-#endif
void (*write_p2m_entry_pre)(struct domain *d,
unsigned long gfn,
l1_pgentry_t old,
@@ -286,6 +285,7 @@ struct p2m_domain {
unsigned int level);
void (*write_p2m_entry_post)(struct p2m_domain *p2m,
unsigned int oflags);
+#endif
#if P2M_AUDIT
long (*audit_p2m)(struct p2m_domain *p2m);
#endif
@@ -788,8 +788,6 @@ int __must_check p2m_set_entry(struct p2
#if defined(CONFIG_HVM)
/* Set up function pointers for PT implementation: only for use by p2m code */
extern void p2m_pt_init(struct p2m_domain *p2m);
-#elif defined(CONFIG_SHADOW_PAGING)
-# define p2m_pt_init shadow_p2m_init
#else
static inline void p2m_pt_init(struct p2m_domain *p2m) {}
#endif
next prev parent reply other threads:[~2021-04-12 14:14 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-12 14:03 [PATCH v2 00/12] x86/p2m: restrict more code to build just for HVM Jan Beulich
2021-04-12 14:05 ` [PATCH v2 01/12] x86/p2m: set_{foreign,mmio}_p2m_entry() are HVM-only Jan Beulich
2021-04-29 13:17 ` Roger Pau Monné
2021-04-29 14:09 ` Jan Beulich
2021-04-29 15:06 ` Roger Pau Monné
2021-04-12 14:06 ` [PATCH v2 02/12] x86/p2m: {,un}map_mmio_regions() " Jan Beulich
2021-04-29 14:48 ` Roger Pau Monné
2021-04-29 15:01 ` Jan Beulich
2021-04-12 14:07 ` [PATCH v2 03/12] x86/mm: the gva_to_gfn() hook is HVM-only Jan Beulich
2021-04-15 16:22 ` Tim Deegan
2021-04-12 14:07 ` [PATCH v2 04/12] AMD/IOMMU: guest IOMMU support is for HVM only Jan Beulich
2021-04-29 15:14 ` Roger Pau Monné
2021-04-12 14:08 ` [PATCH v2 05/12] x86/p2m: change_entry_type_* hooks are HVM-only Jan Beulich
2021-04-29 15:49 ` Roger Pau Monné
2021-04-12 14:08 ` [PATCH v2 06/12] x86/p2m: hardware-log-dirty related " Jan Beulich
2021-04-29 16:05 ` Roger Pau Monné
2021-04-12 14:09 ` [PATCH v2 07/12] x86/p2m: the recalc hook is HVM-only Jan Beulich
2021-04-30 9:27 ` Roger Pau Monné
2021-04-12 14:10 ` [PATCH v2 08/12] x86: mem-access " Jan Beulich
2021-04-12 14:16 ` Tamas K Lengyel
2021-04-12 14:48 ` Isaila Alexandru
2021-04-12 14:12 ` [PATCH v2 09/12] x86: make mem-paging configuarable and default it to off for being unsupported Jan Beulich
2021-04-12 14:18 ` Tamas K Lengyel
2021-04-12 14:47 ` Isaila Alexandru
2021-04-12 14:27 ` Isaila Alexandru
2021-04-30 9:55 ` Roger Pau Monné
2021-04-30 14:16 ` Jan Beulich
2021-04-30 14:37 ` Roger Pau Monné
2021-04-12 14:13 ` [PATCH v2 10/12] x86/p2m: {get,set}_entry hooks and p2m-pt.c are HVM-only Jan Beulich
2021-04-30 10:57 ` Roger Pau Monné
2021-04-12 14:13 ` Jan Beulich [this message]
2021-04-15 16:22 ` [PATCH v2 11/12] x86/p2m: write_p2m_entry_{pre,post} hooks " Tim Deegan
2021-04-12 14:14 ` [PATCH v2 12/12] x86/p2m: re-arrange struct p2m_domain Jan Beulich
2021-04-30 10:59 ` Roger Pau Monné
2021-04-29 9:27 ` Ping: [PATCH v2 00/12] x86/p2m: restrict more code to build just for HVM Jan Beulich
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