* [PATCH v2 0/2] KVM: VMX: cleanup VMXON region allocation
@ 2020-03-05 18:37 Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 1/2] KVM: VMX: rename 'kvm_area' to 'vmxon_region' Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS Vitaly Kuznetsov
0 siblings, 2 replies; 5+ messages in thread
From: Vitaly Kuznetsov @ 2020-03-05 18:37 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Jim Mattson, Sean Christopherson, Wanpeng Li, kvm, linux-kernel
Minor cleanup with no functional change (intended):
- Rename 'kvm_area' to 'vmxon_region'
- Simplify setting revision_id for VMXON region when eVMCS is in use
Changes since v1:
- Patches prefix ('KVM: VMX:' now) [Sean Christopherson]
- Add Sean's R-b to PATCH1
- Do not rename alloc_vmcs_cpu() to alloc_vmx_area_cpu() and add a comment
explaining why we call VMXON region 'VMCS' [Sean Christopherson]
Vitaly Kuznetsov (2):
KVM: VMX: rename 'kvm_area' to 'vmxon_region'
KVM: VMX: untangle VMXON revision_id setting when using eVMCS
arch/x86/kvm/vmx/vmx.c | 42 +++++++++++++++++++-----------------------
arch/x86/kvm/vmx/vmx.h | 12 +++++++++---
2 files changed, 28 insertions(+), 26 deletions(-)
--
2.24.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2 1/2] KVM: VMX: rename 'kvm_area' to 'vmxon_region'
2020-03-05 18:37 [PATCH v2 0/2] KVM: VMX: cleanup VMXON region allocation Vitaly Kuznetsov
@ 2020-03-05 18:37 ` Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS Vitaly Kuznetsov
1 sibling, 0 replies; 5+ messages in thread
From: Vitaly Kuznetsov @ 2020-03-05 18:37 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Jim Mattson, Sean Christopherson, Wanpeng Li, kvm, linux-kernel
The name 'kvm_area' is misleading (as we have way too many areas which are
KVM related), what alloc_kvm_area()/free_kvm_area() functions really do is
allocate/free VMXON region for all CPUs. Rename accordingly.
No functional change intended.
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/vmx/vmx.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 40b1e6138cd5..dab19e4e5f2b 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2635,7 +2635,7 @@ int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
return -ENOMEM;
}
-static void free_kvm_area(void)
+static void free_vmxon_regions(void)
{
int cpu;
@@ -2645,7 +2645,7 @@ static void free_kvm_area(void)
}
}
-static __init int alloc_kvm_area(void)
+static __init int alloc_vmxon_regions(void)
{
int cpu;
@@ -2654,7 +2654,7 @@ static __init int alloc_kvm_area(void)
vmcs = alloc_vmcs_cpu(false, cpu, GFP_KERNEL);
if (!vmcs) {
- free_kvm_area();
+ free_vmxon_regions();
return -ENOMEM;
}
@@ -7815,7 +7815,7 @@ static __init int hardware_setup(void)
return r;
}
- r = alloc_kvm_area();
+ r = alloc_vmxon_regions();
if (r)
nested_vmx_hardware_unsetup();
return r;
@@ -7826,7 +7826,7 @@ static __exit void hardware_unsetup(void)
if (nested)
nested_vmx_hardware_unsetup();
- free_kvm_area();
+ free_vmxon_regions();
}
static bool vmx_check_apicv_inhibit_reasons(ulong bit)
--
2.24.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS
2020-03-05 18:37 [PATCH v2 0/2] KVM: VMX: cleanup VMXON region allocation Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 1/2] KVM: VMX: rename 'kvm_area' to 'vmxon_region' Vitaly Kuznetsov
@ 2020-03-05 18:37 ` Vitaly Kuznetsov
2020-03-05 20:10 ` Sean Christopherson
1 sibling, 1 reply; 5+ messages in thread
From: Vitaly Kuznetsov @ 2020-03-05 18:37 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Jim Mattson, Sean Christopherson, Wanpeng Li, kvm, linux-kernel
As stated in alloc_vmxon_regions(), VMXON region needs to be tagged with
revision id from MSR_IA32_VMX_BASIC even in case of eVMCS. The logic to
do so is not very straightforward: first, we set
hdr.revision_id = KVM_EVMCS_VERSION in alloc_vmcs_cpu() just to reset it
back to vmcs_config.revision_id in alloc_vmxon_regions(). Simplify this by
introducing 'enum vmcs_type' parameter to alloc_vmcs_cpu().
No functional change intended.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/vmx/vmx.c | 32 ++++++++++++++------------------
arch/x86/kvm/vmx/vmx.h | 12 +++++++++---
2 files changed, 23 insertions(+), 21 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index dab19e4e5f2b..697be8823576 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2554,7 +2554,7 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
return 0;
}
-struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
+struct vmcs *alloc_vmcs_cpu(enum vmcs_type type, int cpu, gfp_t flags)
{
int node = cpu_to_node(cpu);
struct page *pages;
@@ -2566,13 +2566,21 @@ struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
vmcs = page_address(pages);
memset(vmcs, 0, vmcs_config.size);
- /* KVM supports Enlightened VMCS v1 only */
- if (static_branch_unlikely(&enable_evmcs))
+ /*
+ * When eVMCS is enabled, vmcs->revision_id needs to be set to the
+ * supported eVMCS version (KVM_EVMCS_VERSION) instead of revision_id
+ * reported by MSR_IA32_VMX_BASIC.
+ *
+ * However, even though not explicitly documented by TLFS, VMXArea
+ * passed as VMXON argument should still be marked with revision_id
+ * reported by physical CPU.
+ */
+ if (type != VMXON_REGION && static_branch_unlikely(&enable_evmcs))
vmcs->hdr.revision_id = KVM_EVMCS_VERSION;
else
vmcs->hdr.revision_id = vmcs_config.revision_id;
- if (shadow)
+ if (type == SHADOW_VMCS_REGION)
vmcs->hdr.shadow_vmcs = 1;
return vmcs;
}
@@ -2652,25 +2660,13 @@ static __init int alloc_vmxon_regions(void)
for_each_possible_cpu(cpu) {
struct vmcs *vmcs;
- vmcs = alloc_vmcs_cpu(false, cpu, GFP_KERNEL);
+ /* The VMXON region is really just a special type of VMCS. */
+ vmcs = alloc_vmcs_cpu(VMXON_REGION, cpu, GFP_KERNEL);
if (!vmcs) {
free_vmxon_regions();
return -ENOMEM;
}
- /*
- * When eVMCS is enabled, alloc_vmcs_cpu() sets
- * vmcs->revision_id to KVM_EVMCS_VERSION instead of
- * revision_id reported by MSR_IA32_VMX_BASIC.
- *
- * However, even though not explicitly documented by
- * TLFS, VMXArea passed as VMXON argument should
- * still be marked with revision_id reported by
- * physical CPU.
- */
- if (static_branch_unlikely(&enable_evmcs))
- vmcs->hdr.revision_id = vmcs_config.revision_id;
-
per_cpu(vmxarea, cpu) = vmcs;
}
return 0;
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index e64da06c7009..4c327030bb9c 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -489,7 +489,13 @@ static inline struct pi_desc *vcpu_to_pi_desc(struct kvm_vcpu *vcpu)
return &(to_vmx(vcpu)->pi_desc);
}
-struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags);
+enum vmcs_type {
+ VMXON_REGION,
+ VMCS_REGION,
+ SHADOW_VMCS_REGION,
+};
+
+struct vmcs *alloc_vmcs_cpu(enum vmcs_type type, int cpu, gfp_t flags);
void free_vmcs(struct vmcs *vmcs);
int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
@@ -498,8 +504,8 @@ void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs);
static inline struct vmcs *alloc_vmcs(bool shadow)
{
- return alloc_vmcs_cpu(shadow, raw_smp_processor_id(),
- GFP_KERNEL_ACCOUNT);
+ return alloc_vmcs_cpu(shadow ? SHADOW_VMCS_REGION : VMCS_REGION,
+ raw_smp_processor_id(), GFP_KERNEL_ACCOUNT);
}
u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa);
--
2.24.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS
2020-03-05 18:37 ` [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS Vitaly Kuznetsov
@ 2020-03-05 20:10 ` Sean Christopherson
2020-03-06 10:06 ` Vitaly Kuznetsov
0 siblings, 1 reply; 5+ messages in thread
From: Sean Christopherson @ 2020-03-05 20:10 UTC (permalink / raw)
To: Vitaly Kuznetsov
Cc: Paolo Bonzini, Jim Mattson, Wanpeng Li, kvm, linux-kernel
On Thu, Mar 05, 2020 at 07:37:25PM +0100, Vitaly Kuznetsov wrote:
> As stated in alloc_vmxon_regions(), VMXON region needs to be tagged with
> revision id from MSR_IA32_VMX_BASIC even in case of eVMCS. The logic to
> do so is not very straightforward: first, we set
> hdr.revision_id = KVM_EVMCS_VERSION in alloc_vmcs_cpu() just to reset it
> back to vmcs_config.revision_id in alloc_vmxon_regions(). Simplify this by
> introducing 'enum vmcs_type' parameter to alloc_vmcs_cpu().
>
> No functional change intended.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
...
> + * However, even though not explicitly documented by TLFS, VMXArea
> + * passed as VMXON argument should still be marked with revision_id
> + * reported by physical CPU.
LOL, nice.
> + */
> + if (type != VMXON_REGION && static_branch_unlikely(&enable_evmcs))
> vmcs->hdr.revision_id = KVM_EVMCS_VERSION;
> else
> vmcs->hdr.revision_id = vmcs_config.revision_id;
>
> - if (shadow)
> + if (type == SHADOW_VMCS_REGION)
> vmcs->hdr.shadow_vmcs = 1;
> return vmcs;
> }
> -struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags);
> +enum vmcs_type {
> + VMXON_REGION,
> + VMCS_REGION,
> + SHADOW_VMCS_REGION,
> +};
> +
> +struct vmcs *alloc_vmcs_cpu(enum vmcs_type type, int cpu, gfp_t flags);
> void free_vmcs(struct vmcs *vmcs);
> int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
> void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
> @@ -498,8 +504,8 @@ void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs);
>
> static inline struct vmcs *alloc_vmcs(bool shadow)
I think it'd be cleaner overall to take "enum vmcs_type" in alloc_vmcs().
Then the ternary operator goes away and the callers (all two of 'em) are
self-documenting. E.g.
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 79c7764c77b1..2c8a0a1386b1 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4566,7 +4566,7 @@ static struct vmcs *alloc_shadow_vmcs(struct kvm_vcpu *vcpu)
WARN_ON(loaded_vmcs == &vmx->vmcs01 && loaded_vmcs->shadow_vmcs);
if (!loaded_vmcs->shadow_vmcs) {
- loaded_vmcs->shadow_vmcs = alloc_vmcs(true);
+ loaded_vmcs->shadow_vmcs = alloc_vmcs(SHADOW_VMCS_REGION);
if (loaded_vmcs->shadow_vmcs)
vmcs_clear(loaded_vmcs->shadow_vmcs);
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 5bdf6919de83..4634f6d7d55a 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2605,7 +2605,7 @@ void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs)
{
- loaded_vmcs->vmcs = alloc_vmcs(false);
+ loaded_vmcs->vmcs = alloc_vmcs(VMCS_REGION);
if (!loaded_vmcs->vmcs)
return -ENOMEM;
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 4c327030bb9c..a5eb92638ac2 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -502,10 +502,10 @@ void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
void loaded_vmcs_init(struct loaded_vmcs *loaded_vmcs);
void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs);
-static inline struct vmcs *alloc_vmcs(bool shadow)
+static inline struct vmcs *alloc_vmcs(enum vmcs_type type)
{
- return alloc_vmcs_cpu(shadow ? SHADOW_VMCS_REGION : VMCS_REGION,
- raw_smp_processor_id(), GFP_KERNEL_ACCOUNT);
+ return alloc_vmcs_cpu(type, raw_smp_processor_id(),
+ GFP_KERNEL_ACCOUNT);
}
u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa);
> {
> - return alloc_vmcs_cpu(shadow, raw_smp_processor_id(),
> - GFP_KERNEL_ACCOUNT);
> + return alloc_vmcs_cpu(shadow ? SHADOW_VMCS_REGION : VMCS_REGION,
> + raw_smp_processor_id(), GFP_KERNEL_ACCOUNT);
> }
>
> u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa);
> --
> 2.24.1
>
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS
2020-03-05 20:10 ` Sean Christopherson
@ 2020-03-06 10:06 ` Vitaly Kuznetsov
0 siblings, 0 replies; 5+ messages in thread
From: Vitaly Kuznetsov @ 2020-03-06 10:06 UTC (permalink / raw)
To: Sean Christopherson
Cc: Paolo Bonzini, Jim Mattson, Wanpeng Li, kvm, linux-kernel
Sean Christopherson <sean.j.christopherson@intel.com> writes:
> On Thu, Mar 05, 2020 at 07:37:25PM +0100, Vitaly Kuznetsov wrote:
>> As stated in alloc_vmxon_regions(), VMXON region needs to be tagged with
>> revision id from MSR_IA32_VMX_BASIC even in case of eVMCS. The logic to
>> do so is not very straightforward: first, we set
>> hdr.revision_id = KVM_EVMCS_VERSION in alloc_vmcs_cpu() just to reset it
>> back to vmcs_config.revision_id in alloc_vmxon_regions(). Simplify this by
>> introducing 'enum vmcs_type' parameter to alloc_vmcs_cpu().
>>
>> No functional change intended.
>>
>> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
>> ---
>
> ...
>
>> + * However, even though not explicitly documented by TLFS, VMXArea
>> + * passed as VMXON argument should still be marked with revision_id
>> + * reported by physical CPU.
>
> LOL, nice.
>
>
>> + */
>> + if (type != VMXON_REGION && static_branch_unlikely(&enable_evmcs))
>> vmcs->hdr.revision_id = KVM_EVMCS_VERSION;
>> else
>> vmcs->hdr.revision_id = vmcs_config.revision_id;
>>
>> - if (shadow)
>> + if (type == SHADOW_VMCS_REGION)
>> vmcs->hdr.shadow_vmcs = 1;
>> return vmcs;
>> }
>
>> -struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags);
>> +enum vmcs_type {
>> + VMXON_REGION,
>> + VMCS_REGION,
>> + SHADOW_VMCS_REGION,
>> +};
>> +
>> +struct vmcs *alloc_vmcs_cpu(enum vmcs_type type, int cpu, gfp_t flags);
>> void free_vmcs(struct vmcs *vmcs);
>> int alloc_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
>> void free_loaded_vmcs(struct loaded_vmcs *loaded_vmcs);
>> @@ -498,8 +504,8 @@ void loaded_vmcs_clear(struct loaded_vmcs *loaded_vmcs);
>>
>> static inline struct vmcs *alloc_vmcs(bool shadow)
>
> I think it'd be cleaner overall to take "enum vmcs_type" in alloc_vmcs().
> Then the ternary operator goes away and the callers (all two of 'em) are
> self-documenting.
Ya, it didn't seem to be needed with my initial suggestion to rename
alloc_vmcs_cpu() to alloc_vmx_area_cpu() because in case we think of
VMXON region as something different from VMCS we have only two options:
normal VMCS or shadow VMCS and bool flag works perfectly.
v3 is on the way, stay tuned!
--
Vitaly
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-03-06 10:06 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2020-03-05 18:37 [PATCH v2 0/2] KVM: VMX: cleanup VMXON region allocation Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 1/2] KVM: VMX: rename 'kvm_area' to 'vmxon_region' Vitaly Kuznetsov
2020-03-05 18:37 ` [PATCH v2 2/2] KVM: VMX: untangle VMXON revision_id setting when using eVMCS Vitaly Kuznetsov
2020-03-05 20:10 ` Sean Christopherson
2020-03-06 10:06 ` Vitaly Kuznetsov
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