[4/6] KVM: X86: Split kvm_update_cpuid()

Commit Message

Xiaoyao Li May 29, 2020, 8:55 a.m. UTC

Split the part of updating KVM states from kvm_update_cpuid(), and put
it into a new kvm_update_state_based_on_cpuid(). So it's clear that
kvm_update_cpuid() is to update guest CPUID settings, while
kvm_update_state_based_on_cpuid() is to update KVM states based on the
updated CPUID settings.

Signed-off-by: Xiaoyao Li <[e-mail]>
---
 arch/x86/kvm/cpuid.c | 38 ++++++++++++++++++++++++--------------
 arch/x86/kvm/cpuid.h |  1 +
 arch/x86/kvm/x86.c   |  1 +
 3 files changed, 26 insertions(+), 14 deletions(-)

Comments

Sean Christopherson June 3, 2020, 1:10 a.m. UTC | #1

On Fri, May 29, 2020 at 04:55:43PM +0800, Xiaoyao Li wrote:
> Split the part of updating KVM states from kvm_update_cpuid(), and put
> it into a new kvm_update_state_based_on_cpuid(). So it's clear that
> kvm_update_cpuid() is to update guest CPUID settings, while
> kvm_update_state_based_on_cpuid() is to update KVM states based on the
> updated CPUID settings.

What about kvm_update_vcpu_model()?  "state" isn't necessarily correct
either.

Xiaoyao Li June 3, 2020, 7:44 a.m. UTC | #2

On 6/3/2020 9:10 AM, Sean Christopherson wrote:
> On Fri, May 29, 2020 at 04:55:43PM +0800, Xiaoyao Li wrote:
>> Split the part of updating KVM states from kvm_update_cpuid(), and put
>> it into a new kvm_update_state_based_on_cpuid(). So it's clear that
>> kvm_update_cpuid() is to update guest CPUID settings, while
>> kvm_update_state_based_on_cpuid() is to update KVM states based on the
>> updated CPUID settings.
> 
> What about kvm_update_vcpu_model()?  "state" isn't necessarily correct
> either.
> 

yeah, it's better.

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c8cb373056f1..a4a2072f5253 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -76,7 +76,6 @@  static int kvm_check_cpuid(struct kvm_vcpu *vcpu)
 void kvm_update_cpuid(struct kvm_vcpu *vcpu)
 {
 	struct kvm_cpuid_entry2 *best;
-	struct kvm_lapic *apic = vcpu->arch.apic;
 
 	best = kvm_find_cpuid_entry(vcpu, 1, 0);
 	if (best) {
@@ -87,13 +86,6 @@  void kvm_update_cpuid(struct kvm_vcpu *vcpu)
 
 		cpuid_entry_change(best, X86_FEATURE_APIC,
 			   vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE);
-
-		if (apic) {
-			if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
-				apic->lapic_timer.timer_mode_mask = 3 << 17;
-			else
-				apic->lapic_timer.timer_mode_mask = 1 << 17;
-		}
 	}
 
 	best = kvm_find_cpuid_entry(vcpu, 7, 0);
@@ -102,13 +94,8 @@  void kvm_update_cpuid(struct kvm_vcpu *vcpu)
 				   kvm_read_cr4_bits(vcpu, X86_CR4_PKE));
 
 	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
-	if (!best) {
-		vcpu->arch.guest_supported_xcr0 = 0;
-	} else {
-		vcpu->arch.guest_supported_xcr0 =
-			(best->eax | ((u64)best->edx << 32)) & supported_xcr0;
+	if (best)
 		best->ebx = xstate_required_size(vcpu->arch.xcr0, false);
-	}
 
 	best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
 	if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) ||
@@ -127,6 +114,27 @@  void kvm_update_cpuid(struct kvm_vcpu *vcpu)
 					   vcpu->arch.ia32_misc_enable_msr &
 					   MSR_IA32_MISC_ENABLE_MWAIT);
 	}
+}
+
+void kvm_update_state_based_on_cpuid(struct kvm_vcpu *vcpu)
+{
+	struct kvm_lapic *apic = vcpu->arch.apic;
+	struct kvm_cpuid_entry2 *best;
+
+	best = kvm_find_cpuid_entry(vcpu, 1, 0);
+	if (best && apic) {
+		if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER))
+			apic->lapic_timer.timer_mode_mask = 3 << 17;
+		else
+			apic->lapic_timer.timer_mode_mask = 1 << 17;
+	}
+
+	best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
+	if (!best)
+		vcpu->arch.guest_supported_xcr0 = 0;
+	else
+		vcpu->arch.guest_supported_xcr0 =
+			(best->eax | ((u64)best->edx << 32)) & supported_xcr0;
 
 	/* Note, maxphyaddr must be updated before tdp_level. */
 	vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
@@ -221,6 +229,7 @@  int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops.cpuid_update(vcpu);
 	kvm_update_cpuid(vcpu);
+	kvm_update_state_based_on_cpuid(vcpu);
 
 out:
 	vfree(cpuid_entries);
@@ -250,6 +259,7 @@  int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 	kvm_apic_set_version(vcpu);
 	kvm_x86_ops.cpuid_update(vcpu);
 	kvm_update_cpuid(vcpu);
+	kvm_update_state_based_on_cpuid(vcpu);
 out:
 	return r;
 }
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index f136de1debad..0ccf9ec4bf55 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -10,6 +10,7 @@  extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
 void kvm_set_cpu_caps(void);
 
 void kvm_update_cpuid(struct kvm_vcpu *vcpu);
+void kvm_update_state_based_on_cpuid(struct kvm_vcpu *vcpu);
 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 					      u32 function, u32 index);
 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dc993b79ae2f..fcb85432d30b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8100,6 +8100,7 @@  static void enter_smm(struct kvm_vcpu *vcpu)
 #endif
 
 	kvm_update_cpuid(vcpu);
+	kvm_update_state_based_on_cpuid(vcpu);
 	kvm_mmu_reset_context(vcpu);
 }