Re: [PATCH 3/6] KVM: x86: introduce kvm_register_clear_available

2021-04-05 Thread Sean Christopherson 
On Thu, Apr 01, 2021, Maxim Levitsky wrote:
> Small refactoring that will be used in the next patch.
> 
> Signed-off-by: Maxim Levitsky 
> ---
>  arch/x86/kvm/kvm_cache_regs.h | 7 +++
>  arch/x86/kvm/svm/svm.c| 6 ++
>  2 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
> index 2e11da2f5621..07d607947805 100644
> --- a/arch/x86/kvm/kvm_cache_regs.h
> +++ b/arch/x86/kvm/kvm_cache_regs.h
> @@ -55,6 +55,13 @@ static inline void kvm_register_mark_available(struct 
> kvm_vcpu *vcpu,
>   __set_bit(reg, (unsigned long *)>arch.regs_avail);
>  }
>  
> +static inline void kvm_register_clear_available(struct kvm_vcpu *vcpu,

I don't love the name, because it makes me think too hard about available vs.
dirty.  :-)   If we drop the optimizations, what if we also drop this patch to
avoid bikeshedding the name?

> +enum kvm_reg reg)
> +{
> + __clear_bit(reg, (unsigned long *)>arch.regs_avail);
> + __clear_bit(reg, (unsigned long *)>arch.regs_dirty);
> +}
> +
>  static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
>  enum kvm_reg reg)
>  {
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 271196400495..2843732299a2 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3880,10 +3880,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct 
> kvm_vcpu *vcpu)
>   vcpu->arch.apf.host_apf_flags =
>   kvm_read_and_reset_apf_flags();
>  
> - if (npt_enabled) {
> - vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
> - vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
> - }
> + if (npt_enabled)
> + kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
>  
>   /*
>* We need to handle MC intercepts here before the vcpu has a chance to
> -- 
> 2.26.2
>

Re: [PATCH 3/6] KVM: x86: introduce kvm_register_clear_available

2021-04-01 Thread Paolo Bonzini 

On 01/04/21 16:18, Maxim Levitsky wrote:

Small refactoring that will be used in the next patch.

Signed-off-by: Maxim Levitsky 
---
  arch/x86/kvm/kvm_cache_regs.h | 7 +++
  arch/x86/kvm/svm/svm.c| 6 ++
  2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 2e11da2f5621..07d607947805 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -55,6 +55,13 @@ static inline void kvm_register_mark_available(struct 
kvm_vcpu *vcpu,
__set_bit(reg, (unsigned long *)>arch.regs_avail);
  }
  
+static inline void kvm_register_clear_available(struct kvm_vcpu *vcpu,

+  enum kvm_reg reg)
+{
+   __clear_bit(reg, (unsigned long *)>arch.regs_avail);
+   __clear_bit(reg, (unsigned long *)>arch.regs_dirty);
+}
+
  static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
   enum kvm_reg reg)
  {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 271196400495..2843732299a2 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3880,10 +3880,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct 
kvm_vcpu *vcpu)
vcpu->arch.apf.host_apf_flags =
kvm_read_and_reset_apf_flags();
  
-	if (npt_enabled) {

-   vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
-   vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
-   }
+   if (npt_enabled)
+   kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
  
  	/*

 * We need to handle MC intercepts here before the vcpu has a chance to



Reviewed-by: Paolo Bonzini

[PATCH 3/6] KVM: x86: introduce kvm_register_clear_available

2021-04-01 Thread Maxim Levitsky 
Small refactoring that will be used in the next patch.

Signed-off-by: Maxim Levitsky 
---
 arch/x86/kvm/kvm_cache_regs.h | 7 +++
 arch/x86/kvm/svm/svm.c| 6 ++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index 2e11da2f5621..07d607947805 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -55,6 +55,13 @@ static inline void kvm_register_mark_available(struct 
kvm_vcpu *vcpu,
__set_bit(reg, (unsigned long *)>arch.regs_avail);
 }
 
+static inline void kvm_register_clear_available(struct kvm_vcpu *vcpu,
+  enum kvm_reg reg)
+{
+   __clear_bit(reg, (unsigned long *)>arch.regs_avail);
+   __clear_bit(reg, (unsigned long *)>arch.regs_dirty);
+}
+
 static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
   enum kvm_reg reg)
 {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 271196400495..2843732299a2 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3880,10 +3880,8 @@ static __no_kcsan fastpath_t svm_vcpu_run(struct 
kvm_vcpu *vcpu)
vcpu->arch.apf.host_apf_flags =
kvm_read_and_reset_apf_flags();
 
-   if (npt_enabled) {
-   vcpu->arch.regs_avail &= ~(1 << VCPU_EXREG_PDPTR);
-   vcpu->arch.regs_dirty &= ~(1 << VCPU_EXREG_PDPTR);
-   }
+   if (npt_enabled)
+   kvm_register_clear_available(vcpu, VCPU_EXREG_PDPTR);
 
/*
 * We need to handle MC intercepts here before the vcpu has a chance to
-- 
2.26.2