KVM: X86: Store L1's TSC scaling ratio in 'struct kvm_vcpu_arch'

Store L1's scaling ratio in the kvm_vcpu_arch struct like we already do
for L1's TSC offset. This allows for easy save/restore when we enter and
then exit the nested guest.

Signed-off-by: Ilias Stamatis <ilstam@amazon.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Message-Id: <20210526184418.28881-3-ilstam@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index dadb545c429f6a76456334def77cfb1e994abce7..8808c8ae9370b32cb7435769a435783947765169 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -707,7 +707,7 @@ struct kvm_vcpu_arch {
        } st;
 
        u64 l1_tsc_offset;
-       u64 tsc_offset;
+       u64 tsc_offset; /* current tsc offset */
        u64 last_guest_tsc;
        u64 last_host_tsc;
        u64 tsc_offset_adjustment;
@@ -721,7 +721,8 @@ struct kvm_vcpu_arch {
        u32 virtual_tsc_khz;
        s64 ia32_tsc_adjust_msr;
        u64 msr_ia32_power_ctl;
-       u64 tsc_scaling_ratio;
+       u64 l1_tsc_scaling_ratio;
+       u64 tsc_scaling_ratio; /* current scaling ratio */
 
        atomic_t nmi_queued;  /* unprocessed asynchronous NMIs */
        unsigned nmi_pending; /* NMI queued after currently running handler */

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index c2a779b688e64195318edd124d4cccebd814cfeb..d3201efa6a07f2bdfa336d6311f7a41aeaf3ea9b 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7453,10 +7453,10 @@ static int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
                delta_tsc = 0;
 
        /* Convert to host delta tsc if tsc scaling is enabled */
-       if (vcpu->arch.tsc_scaling_ratio != kvm_default_tsc_scaling_ratio &&
+       if (vcpu->arch.l1_tsc_scaling_ratio != kvm_default_tsc_scaling_ratio &&
            delta_tsc && u64_shl_div_u64(delta_tsc,
                                kvm_tsc_scaling_ratio_frac_bits,
-                               vcpu->arch.tsc_scaling_ratio, &delta_tsc))
+                               vcpu->arch.l1_tsc_scaling_ratio, &delta_tsc))
                return -ERANGE;
 
        /*

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e838e999ab49de0d66d215c2348cab1c501c3f41..571ee7ef3e0ae7d28b0917e0e574bc0cfb50e075 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2185,6 +2185,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
 
        /* Guest TSC same frequency as host TSC? */
        if (!scale) {
+               vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
                vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
                return 0;
        }
@@ -2211,7 +2212,7 @@ static int set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz, bool scale)
                return -1;
        }
 
-       vcpu->arch.tsc_scaling_ratio = ratio;
+       vcpu->arch.l1_tsc_scaling_ratio = vcpu->arch.tsc_scaling_ratio = ratio;
        return 0;
 }
 
@@ -2223,6 +2224,7 @@ static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
        /* tsc_khz can be zero if TSC calibration fails */
        if (user_tsc_khz == 0) {
                /* set tsc_scaling_ratio to a safe value */
+               vcpu->arch.l1_tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
                vcpu->arch.tsc_scaling_ratio = kvm_default_tsc_scaling_ratio;
                return -1;
        }
@@ -2459,7 +2461,7 @@ static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
 
 static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
 {
-       if (vcpu->arch.tsc_scaling_ratio != kvm_default_tsc_scaling_ratio)
+       if (vcpu->arch.l1_tsc_scaling_ratio != kvm_default_tsc_scaling_ratio)
                WARN_ON(adjustment < 0);
        adjustment = kvm_scale_tsc(vcpu, (u64) adjustment);
        adjust_tsc_offset_guest(vcpu, adjustment);