* [PATCH v4 2/3] KVM: MMU: fix accessed bit set on prefault path
2010-12-02 9:44 [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Xiao Guangrong
@ 2010-12-02 9:45 ` Xiao Guangrong
2010-12-02 9:46 ` [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu Xiao Guangrong
` (2 subsequent siblings)
3 siblings, 0 replies; 9+ messages in thread
From: Xiao Guangrong @ 2010-12-02 9:45 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
Retry #PF is the speculative path, so don't set the accessed bit
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/kvm/mmu.c | 10 ++++++----
1 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 010736e..c6bb449 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2214,7 +2214,8 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
}
static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
- int map_writable, int level, gfn_t gfn, pfn_t pfn)
+ int map_writable, int level, gfn_t gfn, pfn_t pfn,
+ bool prefault)
{
struct kvm_shadow_walk_iterator iterator;
struct kvm_mmu_page *sp;
@@ -2229,7 +2230,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
pte_access &= ~ACC_WRITE_MASK;
mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, pte_access,
0, write, 1, &pt_write,
- level, gfn, pfn, false, map_writable);
+ level, gfn, pfn, prefault, map_writable);
direct_pte_prefetch(vcpu, iterator.sptep);
++vcpu->stat.pf_fixed;
break;
@@ -2321,7 +2322,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn,
if (mmu_notifier_retry(vcpu, mmu_seq))
goto out_unlock;
kvm_mmu_free_some_pages(vcpu);
- r = __direct_map(vcpu, v, write, map_writable, level, gfn, pfn);
+ r = __direct_map(vcpu, v, write, map_writable, level, gfn, pfn,
+ prefault);
spin_unlock(&vcpu->kvm->mmu_lock);
@@ -2684,7 +2686,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
goto out_unlock;
kvm_mmu_free_some_pages(vcpu);
r = __direct_map(vcpu, gpa, write, map_writable,
- level, gfn, pfn);
+ level, gfn, pfn, prefault);
spin_unlock(&vcpu->kvm->mmu_lock);
return r;
--
1.7.0.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu
2010-12-02 9:44 [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Xiao Guangrong
2010-12-02 9:45 ` [PATCH v4 2/3] KVM: MMU: fix accessed bit set on prefault path Xiao Guangrong
@ 2010-12-02 9:46 ` Xiao Guangrong
2010-12-06 9:48 ` Avi Kivity
2010-12-02 9:51 ` Xiao Guangrong
2010-12-03 20:30 ` [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Marcelo Tosatti
3 siblings, 1 reply; 9+ messages in thread
From: Xiao Guangrong @ 2010-12-02 9:46 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs
Changelog:
Just compare cr3 value since It's harmless to instantiate an spte for an
unused translation from Marcelo's comment
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu.c | 2 ++
arch/x86/kvm/paging_tmpl.h | 34 +++++++++++++++++++++++-----------
arch/x86/kvm/x86.c | 6 +++++-
4 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a0c066e..1e876e5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -602,6 +602,7 @@ struct kvm_x86_ops {
struct kvm_arch_async_pf {
u32 token;
gfn_t gfn;
+ unsigned long cr3;
bool direct_map;
};
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c6bb449..3f0d9a0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2607,9 +2607,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
{
struct kvm_arch_async_pf arch;
+
arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id;
arch.gfn = gfn;
arch.direct_map = vcpu->arch.mmu.direct_map;
+ arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu);
return kvm_setup_async_pf(vcpu, gva, gfn, &arch);
}
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 23275d0..437e11a 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -116,7 +116,7 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
*/
static int FNAME(walk_addr_generic)(struct guest_walker *walker,
struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
- gva_t addr, u32 access)
+ gva_t addr, u32 access, bool prefault)
{
pt_element_t pte;
gfn_t table_gfn;
@@ -194,6 +194,13 @@ walk:
#endif
if (!eperm && !rsvd_fault && !(pte & PT_ACCESSED_MASK)) {
+ /*
+ * Don't set gpte accessed bit if it's on
+ * speculative path.
+ */
+ if (prefault)
+ goto error;
+
trace_kvm_mmu_set_accessed_bit(table_gfn, index,
sizeof(pte));
if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn,
@@ -287,10 +294,11 @@ error:
}
static int FNAME(walk_addr)(struct guest_walker *walker,
- struct kvm_vcpu *vcpu, gva_t addr, u32 access)
+ struct kvm_vcpu *vcpu, gva_t addr,
+ u32 access, bool prefault)
{
return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr,
- access);
+ access, prefault);
}
static int FNAME(walk_addr_nested)(struct guest_walker *walker,
@@ -298,7 +306,7 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker,
u32 access)
{
return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu,
- addr, access);
+ addr, access, false);
}
static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu,
@@ -438,7 +446,8 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct guest_walker *gw,
int user_fault, int write_fault, int hlevel,
- int *ptwrite, pfn_t pfn, bool map_writable)
+ int *ptwrite, pfn_t pfn, bool map_writable,
+ bool prefault)
{
unsigned access = gw->pt_access;
struct kvm_mmu_page *sp = NULL;
@@ -512,7 +521,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,
user_fault, write_fault, dirty, ptwrite, it.level,
- gw->gfn, pfn, false, map_writable);
+ gw->gfn, pfn, prefault, map_writable);
FNAME(pte_prefetch)(vcpu, gw, it.sptep);
return it.sptep;
@@ -561,15 +570,18 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
/*
* Look up the guest pte for the faulting address.
*/
- r = FNAME(walk_addr)(&walker, vcpu, addr, error_code);
+ r = FNAME(walk_addr)(&walker, vcpu, addr, error_code, prefault);
/*
* The page is not mapped by the guest. Let the guest handle it.
*/
if (!r) {
pgprintk("%s: guest page fault\n", __func__);
- inject_page_fault(vcpu);
- vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
+ if (!prefault) {
+ inject_page_fault(vcpu);
+ /* reset fork detector */
+ vcpu->arch.last_pt_write_count = 0;
+ }
return 0;
}
@@ -599,7 +611,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
kvm_mmu_free_some_pages(vcpu);
sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
- level, &write_pt, pfn, map_writable);
+ level, &write_pt, pfn, map_writable, prefault);
(void)sptep;
pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,
sptep, *sptep, write_pt);
@@ -685,7 +697,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
gpa_t gpa = UNMAPPED_GVA;
int r;
- r = FNAME(walk_addr)(&walker, vcpu, vaddr, access);
+ r = FNAME(walk_addr)(&walker, vcpu, vaddr, access, false);
if (r) {
gpa = gfn_to_gpa(walker.gfn);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bfd2878..de5e57b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6183,7 +6183,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
{
int r;
- if (!vcpu->arch.mmu.direct_map || !work->arch.direct_map ||
+ if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||
is_error_page(work->page))
return;
@@ -6191,6 +6191,10 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
if (unlikely(r))
return;
+ if (!vcpu->arch.mmu.direct_map &&
+ work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu))
+ return;
+
vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);
}
--
1.7.0.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu
2010-12-02 9:46 ` [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu Xiao Guangrong
@ 2010-12-06 9:48 ` Avi Kivity
2010-12-06 10:22 ` Xiao Guangrong
0 siblings, 1 reply; 9+ messages in thread
From: Avi Kivity @ 2010-12-06 9:48 UTC (permalink / raw)
To: Xiao Guangrong; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
On 12/02/2010 11:46 AM, Xiao Guangrong wrote:
> Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
> when #PF occurs
>
> Changelog:
> Just compare cr3 value since It's harmless to instantiate an spte for an
> unused translation from Marcelo's comment
>
It's not harmless. We could be in a different process, so we have to
re-fetch the gpte. Or we could have switched from one nested guest to
another.
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index c6bb449..3f0d9a0 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -2607,9 +2607,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
> static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
> {
> struct kvm_arch_async_pf arch;
> +
> arch.token = (vcpu->arch.apf.id++<< 12) | vcpu->vcpu_id;
> arch.gfn = gfn;
> arch.direct_map = vcpu->arch.mmu.direct_map;
> + arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu);
>
> return kvm_setup_async_pf(vcpu, gva, gfn,&arch);
> }
> diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
> index 23275d0..437e11a 100644
> --- a/arch/x86/kvm/paging_tmpl.h
> +++ b/arch/x86/kvm/paging_tmpl.h
> @@ -116,7 +116,7 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
> */
> static int FNAME(walk_addr_generic)(struct guest_walker *walker,
> struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
> - gva_t addr, u32 access)
> + gva_t addr, u32 access, bool prefault)
> {
> pt_element_t pte;
> gfn_t table_gfn;
> @@ -194,6 +194,13 @@ walk:
> #endif
>
> if (!eperm&& !rsvd_fault&& !(pte& PT_ACCESSED_MASK)) {
> + /*
> + * Don't set gpte accessed bit if it's on
> + * speculative path.
> + */
> + if (prefault)
> + goto error;
It's actually legal to set the accessed bit on speculative access.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu
2010-12-06 9:48 ` Avi Kivity
@ 2010-12-06 10:22 ` Xiao Guangrong
2010-12-06 13:17 ` Avi Kivity
0 siblings, 1 reply; 9+ messages in thread
From: Xiao Guangrong @ 2010-12-06 10:22 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
Hi Avi,
On 12/06/2010 05:48 PM, Avi Kivity wrote:
> On 12/02/2010 11:46 AM, Xiao Guangrong wrote:
>> Retry #PF for softmmu only when the current vcpu has the same cr3 as
>> the time
>> when #PF occurs
>>
>> Changelog:
>> Just compare cr3 value since It's harmless to instantiate an spte
>> for an
>> unused translation from Marcelo's comment
>>
>
> It's not harmless. We could be in a different process, so we have to
> re-fetch the gpte. Or we could have switched from one nested guest to
> another.
>
But it does this in this patch: re-walk guest page table and fixes guest's
shadow page (not use any info when apf is occurred)
>> if (!eperm&& !rsvd_fault&& !(pte& PT_ACCESSED_MASK)) {
>> + /*
>> + * Don't set gpte accessed bit if it's on
>> + * speculative path.
>> + */
>> + if (prefault)
>> + goto error;
>
> It's actually legal to set the accessed bit on speculative access.
>
Oh, you are right, thanks for your reminder.
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu
2010-12-06 10:22 ` Xiao Guangrong
@ 2010-12-06 13:17 ` Avi Kivity
0 siblings, 0 replies; 9+ messages in thread
From: Avi Kivity @ 2010-12-06 13:17 UTC (permalink / raw)
To: Xiao Guangrong; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
On 12/06/2010 12:22 PM, Xiao Guangrong wrote:
> Hi Avi,
>
> On 12/06/2010 05:48 PM, Avi Kivity wrote:
> > On 12/02/2010 11:46 AM, Xiao Guangrong wrote:
> >> Retry #PF for softmmu only when the current vcpu has the same cr3 as
> >> the time
> >> when #PF occurs
> >>
> >> Changelog:
> >> Just compare cr3 value since It's harmless to instantiate an spte
> >> for an
> >> unused translation from Marcelo's comment
> >>
> >
> > It's not harmless. We could be in a different process, so we have to
> > re-fetch the gpte. Or we could have switched from one nested guest to
> > another.
> >
>
> But it does this in this patch: re-walk guest page table and fixes guest's
> shadow page (not use any info when apf is occurred)
Right. Please resend without the walk_addr() changes. While they're
correct, I'd like to keep that part simpler.
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu
2010-12-02 9:44 [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Xiao Guangrong
2010-12-02 9:45 ` [PATCH v4 2/3] KVM: MMU: fix accessed bit set on prefault path Xiao Guangrong
2010-12-02 9:46 ` [PATCH v4 3/3] KVM: MMU: retry #PF for softmmu Xiao Guangrong
@ 2010-12-02 9:51 ` Xiao Guangrong
2010-12-03 20:30 ` [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Marcelo Tosatti
3 siblings, 0 replies; 9+ messages in thread
From: Xiao Guangrong @ 2010-12-02 9:51 UTC (permalink / raw)
To: Avi Kivity; +Cc: Marcelo Tosatti, Gleb Natapov, LKML, KVM
Retry #PF for softmmu only when the current vcpu has the same cr3 as the time
when #PF occurs
Changelog:
Just compare cr3 value since It's harmless to instantiate an spte for an
unused translation from Marcelo's comment
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
---
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu.c | 2 ++
arch/x86/kvm/paging_tmpl.h | 34 +++++++++++++++++++++++-----------
arch/x86/kvm/x86.c | 6 +++++-
4 files changed, 31 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a0c066e..1e876e5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -602,6 +602,7 @@ struct kvm_x86_ops {
struct kvm_arch_async_pf {
u32 token;
gfn_t gfn;
+ unsigned long cr3;
bool direct_map;
};
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c6bb449..3f0d9a0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2607,9 +2607,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva,
static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn)
{
struct kvm_arch_async_pf arch;
+
arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id;
arch.gfn = gfn;
arch.direct_map = vcpu->arch.mmu.direct_map;
+ arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu);
return kvm_setup_async_pf(vcpu, gva, gfn, &arch);
}
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 23275d0..437e11a 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -116,7 +116,7 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte)
*/
static int FNAME(walk_addr_generic)(struct guest_walker *walker,
struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
- gva_t addr, u32 access)
+ gva_t addr, u32 access, bool prefault)
{
pt_element_t pte;
gfn_t table_gfn;
@@ -194,6 +194,13 @@ walk:
#endif
if (!eperm && !rsvd_fault && !(pte & PT_ACCESSED_MASK)) {
+ /*
+ * Don't set gpte accessed bit if it's on
+ * speculative path.
+ */
+ if (prefault)
+ goto error;
+
trace_kvm_mmu_set_accessed_bit(table_gfn, index,
sizeof(pte));
if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn,
@@ -287,10 +294,11 @@ error:
}
static int FNAME(walk_addr)(struct guest_walker *walker,
- struct kvm_vcpu *vcpu, gva_t addr, u32 access)
+ struct kvm_vcpu *vcpu, gva_t addr,
+ u32 access, bool prefault)
{
return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr,
- access);
+ access, prefault);
}
static int FNAME(walk_addr_nested)(struct guest_walker *walker,
@@ -298,7 +306,7 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker,
u32 access)
{
return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu,
- addr, access);
+ addr, access, false);
}
static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu,
@@ -438,7 +446,8 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw,
static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct guest_walker *gw,
int user_fault, int write_fault, int hlevel,
- int *ptwrite, pfn_t pfn, bool map_writable)
+ int *ptwrite, pfn_t pfn, bool map_writable,
+ bool prefault)
{
unsigned access = gw->pt_access;
struct kvm_mmu_page *sp = NULL;
@@ -512,7 +521,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access,
user_fault, write_fault, dirty, ptwrite, it.level,
- gw->gfn, pfn, false, map_writable);
+ gw->gfn, pfn, prefault, map_writable);
FNAME(pte_prefetch)(vcpu, gw, it.sptep);
return it.sptep;
@@ -561,15 +570,18 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
/*
* Look up the guest pte for the faulting address.
*/
- r = FNAME(walk_addr)(&walker, vcpu, addr, error_code);
+ r = FNAME(walk_addr)(&walker, vcpu, addr, error_code, prefault);
/*
* The page is not mapped by the guest. Let the guest handle it.
*/
if (!r) {
pgprintk("%s: guest page fault\n", __func__);
- inject_page_fault(vcpu);
- vcpu->arch.last_pt_write_count = 0; /* reset fork detector */
+ if (!prefault) {
+ inject_page_fault(vcpu);
+ /* reset fork detector */
+ vcpu->arch.last_pt_write_count = 0;
+ }
return 0;
}
@@ -599,7 +611,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);
kvm_mmu_free_some_pages(vcpu);
sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
- level, &write_pt, pfn, map_writable);
+ level, &write_pt, pfn, map_writable, prefault);
(void)sptep;
pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__,
sptep, *sptep, write_pt);
@@ -685,7 +697,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access,
gpa_t gpa = UNMAPPED_GVA;
int r;
- r = FNAME(walk_addr)(&walker, vcpu, vaddr, access);
+ r = FNAME(walk_addr)(&walker, vcpu, vaddr, access, false);
if (r) {
gpa = gfn_to_gpa(walker.gfn);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index bfd2878..de5e57b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6183,7 +6183,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
{
int r;
- if (!vcpu->arch.mmu.direct_map || !work->arch.direct_map ||
+ if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) ||
is_error_page(work->page))
return;
@@ -6191,6 +6191,10 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work)
if (unlikely(r))
return;
+ if (!vcpu->arch.mmu.direct_map &&
+ work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu))
+ return;
+
vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true);
}
--
1.7.0.4
^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault'
2010-12-02 9:44 [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Xiao Guangrong
` (2 preceding siblings ...)
2010-12-02 9:51 ` Xiao Guangrong
@ 2010-12-03 20:30 ` Marcelo Tosatti
2010-12-06 9:32 ` Gleb Natapov
3 siblings, 1 reply; 9+ messages in thread
From: Marcelo Tosatti @ 2010-12-03 20:30 UTC (permalink / raw)
To: Xiao Guangrong; +Cc: Avi Kivity, Gleb Natapov, LKML, KVM
On Thu, Dec 02, 2010 at 05:44:43PM +0800, Xiao Guangrong wrote:
> It's the speculative path if 'no_apf = 1' and we will specially handle this
> speculative path in the later patch, so 'prefault' is better to fit the sense
>
> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> ---
> arch/x86/include/asm/kvm_host.h | 3 ++-
> arch/x86/kvm/mmu.c | 18 +++++++++---------
> arch/x86/kvm/paging_tmpl.h | 4 ++--
> 3 files changed, 13 insertions(+), 12 deletions(-)
Looks good to me. Avi, Gleb?
^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault'
2010-12-03 20:30 ` [PATCH v4 1/3] KVM: MMU: rename 'no_apf' to 'prefault' Marcelo Tosatti
@ 2010-12-06 9:32 ` Gleb Natapov
0 siblings, 0 replies; 9+ messages in thread
From: Gleb Natapov @ 2010-12-06 9:32 UTC (permalink / raw)
To: Marcelo Tosatti; +Cc: Xiao Guangrong, Avi Kivity, LKML, KVM
On Fri, Dec 03, 2010 at 06:30:55PM -0200, Marcelo Tosatti wrote:
> On Thu, Dec 02, 2010 at 05:44:43PM +0800, Xiao Guangrong wrote:
> > It's the speculative path if 'no_apf = 1' and we will specially handle this
> > speculative path in the later patch, so 'prefault' is better to fit the sense
> >
> > Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
> > ---
> > arch/x86/include/asm/kvm_host.h | 3 ++-
> > arch/x86/kvm/mmu.c | 18 +++++++++---------
> > arch/x86/kvm/paging_tmpl.h | 4 ++--
> > 3 files changed, 13 insertions(+), 12 deletions(-)
>
> Looks good to me. Avi, Gleb?
Looks mostly OK to me too. Third patch check only cr3 but cr4 & efer can
affect paging too, but since page fault is not injected anyway in case
of an error and for most guests cr4 & efer shouldn't change frequently I
guess this is OK.
--
Gleb.
^ permalink raw reply [flat|nested] 9+ messages in thread