On Tue, Jul 29, 2025, Chao Gao wrote:
> On Mon, Jul 28, 2025 at 03:31:41PM -0700, Xin Li wrote:
> >> /* Set L1 segment info according to Intel SDM
> >> 27.5.2 Loading Host Segment and Descriptor-Table Registers */
> >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> >> index 7543dac7ae70..11d84075cd14 100644
> >> --- a/arch/x86/kvm/x86.c
> >> +++ b/arch/x86/kvm/x86.c
> >> @@ -1929,33 +1929,35 @@ static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu,
> >> __kvm_get_msr);
> >> }
> >> -int kvm_get_msr_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 *data)
> >> +int kvm_emulate_msr_read_with_filter(struct kvm_vcpu *vcpu, u32 index,
> >> + u64 *data)
> >
> >I think the extra new line doesn't improve readability, but it's the
> >maintainer's call.
> >
>
> Sure. Seems "let it poke out" is Sean's preference. I saw he made similar
> requests several times. e.g.,
Depends on the situation. I'd probably mentally flip a coin in this case.
But what I'd actually do here is choose names that are (a) less verbose and (b)
capture the relationship between the APIs. Instead of:
int kvm_emulate_msr_read_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 *data);
int kvm_emulate_msr_write_with_filter(struct kvm_vcpu *vcpu, u32 index, u64 data);
int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data);
int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data);
rename to:
int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data);
int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data);
int __kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data);
int __kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data);
And then we can do a follow-up patch to solidify the relationship:
--
From: Sean Christopherson <seanjc@xxxxxxxxxx>
Date: Tue, 29 Jul 2025 11:13:48 -0700
Subject: [PATCH] KVM: x86: Use double-underscore read/write MSR helpers as
appropriate
Use the double-underscore helpers for emulating MSR reads and writes in
he no-underscore versions to better capture the relationship between the
two sets of APIs (the double-underscore versions don't honor userspace MSR
filters).
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 09b106a5afdf..65c787bcfe8b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1932,11 +1932,24 @@ static int kvm_get_msr_ignored_check(struct kvm_vcpu *vcpu,
__kvm_get_msr);
}
+int __kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data)
+{
+ return kvm_get_msr_ignored_check(vcpu, index, data, false);
+}
+EXPORT_SYMBOL_GPL(__kvm_emulate_msr_read);
+
+int __kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data)
+{
+ return kvm_set_msr_ignored_check(vcpu, index, data, false);
+}
+EXPORT_SYMBOL_GPL(__kvm_emulate_msr_write);
+
int kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data)
{
if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_READ))
return KVM_MSR_RET_FILTERED;
- return kvm_get_msr_ignored_check(vcpu, index, data, false);
+
+ return __kvm_emulate_msr_read(vcpu, index, data);
}
EXPORT_SYMBOL_GPL(kvm_emulate_msr_read);
@@ -1944,21 +1957,11 @@ int kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data)
{
if (!kvm_msr_allowed(vcpu, index, KVM_MSR_FILTER_WRITE))
return KVM_MSR_RET_FILTERED;
- return kvm_set_msr_ignored_check(vcpu, index, data, false);
+
+ return __kvm_emulate_msr_write(vcpu, index, data);
}
EXPORT_SYMBOL_GPL(kvm_emulate_msr_write);
-int __kvm_emulate_msr_read(struct kvm_vcpu *vcpu, u32 index, u64 *data)
-{
- return kvm_get_msr_ignored_check(vcpu, index, data, false);
-}
-EXPORT_SYMBOL_GPL(__kvm_emulate_msr_read);
-
-int __kvm_emulate_msr_write(struct kvm_vcpu *vcpu, u32 index, u64 data)
-{
- return kvm_set_msr_ignored_check(vcpu, index, data, false);
-}
-EXPORT_SYMBOL_GPL(__kvm_emulate_msr_write);
static void complete_userspace_rdmsr(struct kvm_vcpu *vcpu)
{
base-commit: 1877e7b0749cbaa2d2ba4056eeda93adb373f7d4
--
