Re: [RESEND PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
On 07/14/2014 10:27 PM, Gleb Natapov wrote: .. if (likely(kvm-arch.ept_identity_pagetable_done)) return 1; - ret = 0; identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT; + + mutex_lock(kvm-slots_lock); Why move this out of alloc_identity_pagetable()? Referring to the original code, I think mutex_lock(kvm-slots_lock) is used to protect kvm-arch.ept_identity_pagetable. If two or more threads try to modify it at the same time, the mutex ensures that the identity table is only allocated once. Now, we dropped kvm-arch.ept_identity_pagetable. And use kvm-arch.ept_identity_pagetable_done to check if the identity table is allocated and initialized. So we should protect memory slot operation in alloc_identity_pagetable() and kvm-arch.ept_identity_pagetable_done with this mutex. Of course, I can see that the name slots_lock indicates that it may be used to protect the memory slot operation only. Maybe move it out here is not suitable. If I'm wrong, please tell me. No, you are right that besides memory slot creation slots_lock protects checking of ept_identity_pagetable here, but after you patch ept_identity_pagetable_done is tested outside of slots_lock so the allocation can happen twice, no? Oh, yes. Will fix it in the next version. Thanks. -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RESEND PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
Hi Gleb,
Please see below.
On 07/12/2014 03:44 PM, Gleb Natapov wrote:
On Wed, Jul 09, 2014 at 10:08:03AM +0800, Tang Chen wrote:
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chentangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..fe2e5f4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
Why move this out of alloc_identity_pagetable()?
Referring to the original code, I think mutex_lock(kvm-slots_lock) is
used
to protect kvm-arch.ept_identity_pagetable. If two or more threads try to
modify it at the same time, the mutex ensures that the identity table is
only
allocated once.
Now, we dropped kvm-arch.ept_identity_pagetable. And use
kvm-arch.ept_identity_pagetable_done
to check if the identity table is allocated and initialized. So we
should protect
memory slot operation in alloc_identity_pagetable() and
kvm-arch.ept_identity_pagetable_done
with this mutex.
Of course, I can see that the name slots_lock indicates that it may be
used
to protect the memory slot operation only. Maybe move it out here is not
suitable.
If I'm wrong, please tell me.
+ r = alloc_identity_pagetable(kvm);
+ if (r)
+ goto out2;
+
idx = srcu_read_lock(kvm-srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r 0)
@@ -3953,6 +3954,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1;
out:
srcu_read_unlock(kvm-srcu, idx);
+
+out2:
+ mutex_unlock(kvm-slots_lock);
return ret;
}
@@ -4006,9 +4010,6 @@ static int alloc_identity_pagetable(struct kvm *kvm)
struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0;
- mutex_lock(kvm-slots_lock);
- if (kvm-arch.ept_identity_pagetable)
- goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr =
@@ -4025,9 +4026,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
goto out;
}
- kvm-arch.ept_identity_pagetable = page;
I think we can drop gfn_to_page() above too now. Why would we need it?
Yes, will remove it in the next version.
Thanks.
out:
- mutex_unlock(kvm-slots_lock);
return r;
}
@@ -7583,8 +7582,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm,
unsigned int id)
kvm-arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM;
- if (alloc_identity_pagetable(kvm) != 0)
- goto free_vmcs;
if (!init_rmode_identity_map(kvm))
goto free_vmcs;
}
--
1.8.3.1
--
Gleb.
.
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Re: [RESEND PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
On Mon, Jul 14, 2014 at 05:17:04PM +0800, Tang Chen wrote:
On 07/12/2014 03:44 PM, Gleb Natapov wrote:
On Wed, Jul 09, 2014 at 10:08:03AM +0800, Tang Chen wrote:
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chentangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h
b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..fe2e5f4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
Why move this out of alloc_identity_pagetable()?
Referring to the original code, I think mutex_lock(kvm-slots_lock) is used
to protect kvm-arch.ept_identity_pagetable. If two or more threads try to
modify it at the same time, the mutex ensures that the identity table is
only
allocated once.
Now, we dropped kvm-arch.ept_identity_pagetable. And use
kvm-arch.ept_identity_pagetable_done
to check if the identity table is allocated and initialized. So we should
protect
memory slot operation in alloc_identity_pagetable() and
kvm-arch.ept_identity_pagetable_done
with this mutex.
Of course, I can see that the name slots_lock indicates that it may be
used
to protect the memory slot operation only. Maybe move it out here is not
suitable.
If I'm wrong, please tell me.
No, you are right that besides memory slot creation slots_lock protects checking
of ept_identity_pagetable here, but after you patch ept_identity_pagetable_done
is
tested outside of slots_lock so the allocation can happen twice, no?
--
Gleb.
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Re: [RESEND PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
On Wed, Jul 09, 2014 at 10:08:03AM +0800, Tang Chen wrote:
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chen tangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..fe2e5f4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
Why move this out of alloc_identity_pagetable()?
+ r = alloc_identity_pagetable(kvm);
+ if (r)
+ goto out2;
+
idx = srcu_read_lock(kvm-srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r 0)
@@ -3953,6 +3954,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1;
out:
srcu_read_unlock(kvm-srcu, idx);
+
+out2:
+ mutex_unlock(kvm-slots_lock);
return ret;
}
@@ -4006,9 +4010,6 @@ static int alloc_identity_pagetable(struct kvm *kvm)
struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0;
- mutex_lock(kvm-slots_lock);
- if (kvm-arch.ept_identity_pagetable)
- goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr =
@@ -4025,9 +4026,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
goto out;
}
- kvm-arch.ept_identity_pagetable = page;
I think we can drop gfn_to_page() above too now. Why would we need it?
out:
- mutex_unlock(kvm-slots_lock);
return r;
}
@@ -7583,8 +7582,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm
*kvm, unsigned int id)
kvm-arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM;
- if (alloc_identity_pagetable(kvm) != 0)
- goto free_vmcs;
if (!init_rmode_identity_map(kvm))
goto free_vmcs;
}
--
1.8.3.1
--
Gleb.
--
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[PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chen tangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..5532ac8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
+ r = alloc_identity_pagetable(kvm);
+ if (r)
+ goto out;
+
idx = srcu_read_lock(kvm-srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r 0)
@@ -3953,6 +3954,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1;
out:
srcu_read_unlock(kvm-srcu, idx);
+
+out2:
+ mutex_unlock(kvm-slots_lock);
return ret;
}
@@ -4006,9 +4010,6 @@ static int alloc_identity_pagetable(struct kvm *kvm)
struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0;
- mutex_lock(kvm-slots_lock);
- if (kvm-arch.ept_identity_pagetable)
- goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr =
@@ -4025,9 +4026,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
goto out;
}
- kvm-arch.ept_identity_pagetable = page;
out:
- mutex_unlock(kvm-slots_lock);
return r;
}
@@ -7583,8 +7582,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm,
unsigned int id)
kvm-arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM;
- if (alloc_identity_pagetable(kvm) != 0)
- goto free_vmcs;
if (!init_rmode_identity_map(kvm))
goto free_vmcs;
}
--
1.8.3.1
--
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Re: [PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
On 07/08/2014 09:01 PM, Tang Chen wrote:
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chentangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..5532ac8 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
+ r = alloc_identity_pagetable(kvm);
+ if (r)
+ goto out;
s/goto out/goto out2
Will resend the patch soon.
+
idx = srcu_read_lock(kvm-srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r 0)
@@ -3953,6 +3954,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1;
out:
srcu_read_unlock(kvm-srcu, idx);
+
+out2:
+ mutex_unlock(kvm-slots_lock);
return ret;
}
@@ -4006,9 +4010,6 @@ static int alloc_identity_pagetable(struct kvm *kvm)
struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0;
- mutex_lock(kvm-slots_lock);
- if (kvm-arch.ept_identity_pagetable)
- goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr =
@@ -4025,9 +4026,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
goto out;
}
- kvm-arch.ept_identity_pagetable = page;
out:
- mutex_unlock(kvm-slots_lock);
return r;
}
@@ -7583,8 +7582,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm,
unsigned int id)
kvm-arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM;
- if (alloc_identity_pagetable(kvm) != 0)
- goto free_vmcs;
if (!init_rmode_identity_map(kvm))
goto free_vmcs;
}
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[RESEND PATCH v2 4/5] kvm: Remove ept_identity_pagetable from struct kvm_arch.
kvm_arch-ept_identity_pagetable holds the ept identity pagetable page. But
it is never used to refer to the page at all.
In vcpu initialization, it indicates two things:
1. indicates if ept page is allocated
2. indicates if a memory slot for identity page is initialized
Actually, kvm_arch-ept_identity_pagetable_done is enough to tell if the ept
identity pagetable is initialized. So we can remove ept_identity_pagetable.
Signed-off-by: Tang Chen tangc...@cn.fujitsu.com
---
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx.c | 25 +++--
2 files changed, 11 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 4931415..62f973e 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -578,7 +578,6 @@ struct kvm_arch {
gpa_t wall_clock;
- struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
gpa_t ept_identity_map_addr;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0918635e..fe2e5f4 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -741,6 +741,7 @@ static void vmx_sync_pir_to_irr_dummy(struct kvm_vcpu
*vcpu);
static void copy_vmcs12_to_shadow(struct vcpu_vmx *vmx);
static void copy_shadow_to_vmcs12(struct vcpu_vmx *vmx);
static bool vmx_mpx_supported(void);
+static int alloc_identity_pagetable(struct kvm *kvm);
static DEFINE_PER_CPU(struct vmcs *, vmxarea);
static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
@@ -3921,21 +3922,21 @@ out:
static int init_rmode_identity_map(struct kvm *kvm)
{
- int i, idx, r, ret;
+ int i, idx, r, ret = 0;
pfn_t identity_map_pfn;
u32 tmp;
if (!enable_ept)
return 1;
- if (unlikely(!kvm-arch.ept_identity_pagetable)) {
- printk(KERN_ERR EPT: identity-mapping pagetable
- haven't been allocated!\n);
- return 0;
- }
if (likely(kvm-arch.ept_identity_pagetable_done))
return 1;
- ret = 0;
identity_map_pfn = kvm-arch.ept_identity_map_addr PAGE_SHIFT;
+
+ mutex_lock(kvm-slots_lock);
+ r = alloc_identity_pagetable(kvm);
+ if (r)
+ goto out2;
+
idx = srcu_read_lock(kvm-srcu);
r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
if (r 0)
@@ -3953,6 +3954,9 @@ static int init_rmode_identity_map(struct kvm *kvm)
ret = 1;
out:
srcu_read_unlock(kvm-srcu, idx);
+
+out2:
+ mutex_unlock(kvm-slots_lock);
return ret;
}
@@ -4006,9 +4010,6 @@ static int alloc_identity_pagetable(struct kvm *kvm)
struct kvm_userspace_memory_region kvm_userspace_mem;
int r = 0;
- mutex_lock(kvm-slots_lock);
- if (kvm-arch.ept_identity_pagetable)
- goto out;
kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
kvm_userspace_mem.flags = 0;
kvm_userspace_mem.guest_phys_addr =
@@ -4025,9 +4026,7 @@ static int alloc_identity_pagetable(struct kvm *kvm)
goto out;
}
- kvm-arch.ept_identity_pagetable = page;
out:
- mutex_unlock(kvm-slots_lock);
return r;
}
@@ -7583,8 +7582,6 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm,
unsigned int id)
kvm-arch.ept_identity_map_addr =
VMX_EPT_IDENTITY_PAGETABLE_ADDR;
err = -ENOMEM;
- if (alloc_identity_pagetable(kvm) != 0)
- goto free_vmcs;
if (!init_rmode_identity_map(kvm))
goto free_vmcs;
}
--
1.8.3.1
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