# HG changeset patch
# User Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
# Date 1181922668 -3600
# Node ID 1feb91894e11d3b1fac3b4c38b1eb325c8acd20b
# Parent 56548d9a7ba7a5fb39b31db9b018217e259233c3
[HVM] HAP tidying.
Tighten up locking discipline, dead/useless code and unnecessary VMEXITS.
Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
---
xen/arch/x86/hvm/svm/vmcb.c | 10 +++
xen/arch/x86/mm/hap/hap.c | 123 +++++++++++++++-----------------------------
xen/arch/x86/mm/p2m.c | 8 ++
3 files changed, 58 insertions(+), 83 deletions(-)
diff -r 56548d9a7ba7 -r 1feb91894e11 xen/arch/x86/hvm/svm/vmcb.c
--- a/xen/arch/x86/hvm/svm/vmcb.c Fri Jun 15 16:30:10 2007 +0100
+++ b/xen/arch/x86/hvm/svm/vmcb.c Fri Jun 15 16:51:08 2007 +0100
@@ -236,6 +236,16 @@ static int construct_vmcb(struct vcpu *v
vmcb->g_pat = 0x0007040600070406ULL; /* guest PAT */
vmcb->h_cr3 = pagetable_get_paddr(v->domain->arch.phys_table);
vmcb->cr4 = arch_svm->cpu_shadow_cr4 = 0;
+
+ /* No point in intercepting CR0/3/4 reads, because the hardware
+ * will return the guest versions anyway. */
+ vmcb->cr_intercepts &= ~(CR_INTERCEPT_CR0_READ
+ |CR_INTERCEPT_CR3_READ
+ |CR_INTERCEPT_CR4_READ);
+
+ /* No point in intercepting INVLPG if we don't have shadow pagetables
+ * that need to be fixed up. */
+ vmcb->general1_intercepts &= ~GENERAL1_INTERCEPT_INVLPG;
}
else
{
diff -r 56548d9a7ba7 -r 1feb91894e11 xen/arch/x86/mm/hap/hap.c
--- a/xen/arch/x86/mm/hap/hap.c Fri Jun 15 16:30:10 2007 +0100
+++ b/xen/arch/x86/mm/hap/hap.c Fri Jun 15 16:51:08 2007 +0100
@@ -55,14 +55,14 @@
/* hap code to call when log_dirty is enable. return 0 if no problem found. */
int hap_enable_log_dirty(struct domain *d)
{
+ /* turn on PG_log_dirty bit in paging mode */
hap_lock(d);
- /* turn on PG_log_dirty bit in paging mode */
d->arch.paging.mode |= PG_log_dirty;
+ hap_unlock(d);
+
/* set l1e entries of P2M table to NOT_WRITABLE. */
p2m_set_flags_global(d, (_PAGE_PRESENT|_PAGE_USER));
- flush_tlb_all_pge();
- hap_unlock(d);
-
+ flush_tlb_mask(d->domain_dirty_cpumask);
return 0;
}
@@ -70,19 +70,20 @@ int hap_disable_log_dirty(struct domain
{
hap_lock(d);
d->arch.paging.mode &= ~PG_log_dirty;
+ hap_unlock(d);
+
/* set l1e entries of P2M table with normal mode */
- p2m_set_flags_global(d, __PAGE_HYPERVISOR|_PAGE_USER);
- hap_unlock(d);
-
- return 1;
+ p2m_set_flags_global(d, __PAGE_HYPERVISOR|_PAGE_USER);
+ return 0;
}
void hap_clean_dirty_bitmap(struct domain *d)
{
/* mark physical memory as NOT_WRITEABLE and flush the TLB */
p2m_set_flags_global(d, (_PAGE_PRESENT|_PAGE_USER));
- flush_tlb_all_pge();
-}
+ flush_tlb_mask(d->domain_dirty_cpumask);
+}
+
/************************************************/
/* HAP SUPPORT FUNCTIONS */
/************************************************/
@@ -268,6 +269,7 @@ void hap_install_xen_entries_in_l2h(stru
{
struct domain *d = v->domain;
l2_pgentry_t *sl2e;
+ l3_pgentry_t *p2m;
int i;
@@ -290,23 +292,18 @@ void hap_install_xen_entries_in_l2h(stru
sl2e[l2_table_offset(LINEAR_PT_VIRT_START) + i] =
l2e_empty();
- if ( paging_mode_translate(d) )
+ /* Install the domain-specific p2m table */
+ ASSERT(pagetable_get_pfn(d->arch.phys_table) != 0);
+ p2m = hap_map_domain_page(pagetable_get_mfn(d->arch.phys_table));
+ for ( i = 0; i < MACHPHYS_MBYTES>>1; i++ )
{
- /* Install the domain-specific p2m table */
- l3_pgentry_t *p2m;
- ASSERT(pagetable_get_pfn(d->arch.phys_table) != 0);
- p2m = hap_map_domain_page(pagetable_get_mfn(d->arch.phys_table));
- for ( i = 0; i < MACHPHYS_MBYTES>>1; i++ )
- {
- sl2e[l2_table_offset(RO_MPT_VIRT_START) + i] =
- (l3e_get_flags(p2m[i]) & _PAGE_PRESENT)
- ? l2e_from_pfn(mfn_x(_mfn(l3e_get_pfn(p2m[i]))),
- __PAGE_HYPERVISOR)
- : l2e_empty();
- }
- hap_unmap_domain_page(p2m);
- }
-
+ sl2e[l2_table_offset(RO_MPT_VIRT_START) + i] =
+ (l3e_get_flags(p2m[i]) & _PAGE_PRESENT)
+ ? l2e_from_pfn(mfn_x(_mfn(l3e_get_pfn(p2m[i]))),
+ __PAGE_HYPERVISOR)
+ : l2e_empty();
+ }
+ hap_unmap_domain_page(p2m);
hap_unmap_domain_page(sl2e);
}
#endif
@@ -565,61 +562,37 @@ void hap_vcpu_init(struct vcpu *v)
/************************************************/
/* HAP PAGING MODE FUNCTIONS */
/************************************************/
-/* In theory, hap should not intercept guest page fault. This function can
- * be recycled to handle host/nested page fault, if needed.
+/*
+ * HAP guests can handle page faults (in the guest page tables) without
+ * needing any action from Xen, so we should not be intercepting them.
*/
int hap_page_fault(struct vcpu *v, unsigned long va,
struct cpu_user_regs *regs)
{
- HERE_I_AM;
+ HAP_ERROR("Intercepted a guest #PF (%u:%u) with HAP enabled.\n",
+ v->domain->domain_id, v->vcpu_id);
domain_crash(v->domain);
return 0;
}
-/* called when guest issues a invlpg request.
- * Return 1 if need to issue page invalidation on CPU; Return 0 if does not
- * need to do so.
+/*
+ * HAP guests can handle invlpg without needing any action from Xen, so
+ * should not be intercepting it.
*/
int hap_invlpg(struct vcpu *v, unsigned long va)
{
- HERE_I_AM;
+ HAP_ERROR("Intercepted a guest INVLPG (%u:%u) with HAP enabled.\n",
+ v->domain->domain_id, v->vcpu_id);
+ domain_crash(v->domain);
return 0;
}
+/*
+ * HAP guests do not need to take any action on CR3 writes (they are still
+ * intercepted, so that Xen's copy of the guest's CR3 can be kept in sync.)
+ */
void hap_update_cr3(struct vcpu *v, int do_locking)
{
- struct domain *d = v->domain;
- mfn_t gmfn;
-
- HERE_I_AM;
- /* Don't do anything on an uninitialised vcpu */
- if ( !is_hvm_domain(d) && !v->is_initialised )
- {
- ASSERT(v->arch.cr3 == 0);
- return;
- }
-
- if ( do_locking )
- hap_lock(v->domain);
-
- ASSERT(hap_locked_by_me(v->domain));
- ASSERT(v->arch.paging.mode);
-
- gmfn = pagetable_get_mfn(v->arch.guest_table);
-
- make_cr3(v, pagetable_get_pfn(v->arch.monitor_table));
-
- hvm_update_guest_cr3(v, pagetable_get_paddr(v->arch.monitor_table));
-
- HAP_PRINTK("d=%u v=%u guest_table=%05lx, monitor_table = %05lx\n",
- d->domain_id, v->vcpu_id,
- (unsigned long)pagetable_get_pfn(v->arch.guest_table),
- (unsigned long)pagetable_get_pfn(v->arch.monitor_table));
-
- flush_tlb_mask(d->domain_dirty_cpumask);
-
- if ( do_locking )
- hap_unlock(v->domain);
}
void hap_update_paging_modes(struct vcpu *v)
@@ -647,7 +620,7 @@ void hap_update_paging_modes(struct vcpu
v->arch.paging.mode = &hap_paging_real_mode;
}
- v->arch.paging.translate_enabled = !!hvm_paging_enabled(v);
+ v->arch.paging.translate_enabled = !!hvm_paging_enabled(v);
if ( pagetable_is_null(v->arch.monitor_table) ) {
mfn_t mmfn = hap_make_monitor_table(v);
@@ -655,7 +628,6 @@ void hap_update_paging_modes(struct vcpu
make_cr3(v, mfn_x(mmfn));
}
- flush_tlb_mask(d->domain_dirty_cpumask);
hap_unlock(d);
}
@@ -702,29 +674,18 @@ hap_write_p2m_entry(struct vcpu *v, unsi
hap_write_p2m_entry(struct vcpu *v, unsigned long gfn, l1_pgentry_t *p,
l1_pgentry_t new, unsigned int level)
{
- int do_locking;
-
- /* This function can be called from two directions (P2M and log dirty). We
- * need to make sure this lock has been held or not.
- */
- do_locking = !hap_locked_by_me(v->domain);
-
- if ( do_locking )
- hap_lock(v->domain);
+ hap_lock(v->domain);
safe_write_pte(p, new);
#if CONFIG_PAGING_LEVELS == 3
/* install P2M in monitor table for PAE Xen */
- if ( level == 3 ) {
+ if ( level == 3 )
/* We have written to the p2m l3: need to sync the per-vcpu
* copies of it in the monitor tables */
p2m_install_entry_in_monitors(v->domain, (l3_pgentry_t *)p);
-
- }
#endif
- if ( do_locking )
- hap_unlock(v->domain);
+ hap_unlock(v->domain);
}
/* Entry points into this mode of the hap code. */
diff -r 56548d9a7ba7 -r 1feb91894e11 xen/arch/x86/mm/p2m.c
--- a/xen/arch/x86/mm/p2m.c Fri Jun 15 16:30:10 2007 +0100
+++ b/xen/arch/x86/mm/p2m.c Fri Jun 15 16:51:08 2007 +0100
@@ -32,9 +32,13 @@
#define P2M_AUDIT 0
#define P2M_DEBUGGING 1
-/* The P2M lock. This protects all updates to the p2m table.
+/*
+ * The P2M lock. This protects all updates to the p2m table.
* Updates are expected to be safe against concurrent reads,
- * which do *not* require the lock */
+ * which do *not* require the lock.
+ *
+ * Locking discipline: always acquire this lock before the shadow or HAP one
+ */
#define p2m_lock_init(_d) \
do { \
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