KVM: x86: Convert TSC writes to TSC offset writes (f4e1b3c8) · Commits · 戴 / test

arch/x86/kvm/svm.c

+17 −14

Original line number	Diff line number	Diff line
		@@ -701,6 +701,20 @@ static void init_sys_seg(struct vmcb_seg *seg, uint32_t type)
		seg->base = 0;
		}

		static void svm_write_tsc_offset(struct kvm_vcpu *vcpu, u64 offset)
		{
		struct vcpu_svm *svm = to_svm(vcpu);
		u64 g_tsc_offset = 0;

		if (is_nested(svm)) {
		g_tsc_offset = svm->vmcb->control.tsc_offset -
		svm->nested.hsave->control.tsc_offset;
		svm->nested.hsave->control.tsc_offset = offset;
		}

		svm->vmcb->control.tsc_offset = offset + g_tsc_offset;
		}

		static void init_vmcb(struct vcpu_svm *svm)
		{
		struct vmcb_control_area *control = &svm->vmcb->control;
		@@ -901,7 +915,7 @@ static struct kvm_vcpu svm_create_vcpu(struct kvm kvm, unsigned int id)
		svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
		svm->asid_generation = 0;
		init_vmcb(svm);
		svm->vmcb->control.tsc_offset = 0-native_read_tsc();
		svm_write_tsc_offset(&svm->vcpu, 0-native_read_tsc());

		err = fx_init(&svm->vcpu);
		if (err)
		@@ -2566,20 +2580,9 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
		struct vcpu_svm *svm = to_svm(vcpu);

		switch (ecx) {
		case MSR_IA32_TSC: {
		u64 tsc_offset = data - native_read_tsc();
		u64 g_tsc_offset = 0;

		if (is_nested(svm)) {
		g_tsc_offset = svm->vmcb->control.tsc_offset -
		svm->nested.hsave->control.tsc_offset;
		svm->nested.hsave->control.tsc_offset = tsc_offset;
		}

		svm->vmcb->control.tsc_offset = tsc_offset + g_tsc_offset;

		case MSR_IA32_TSC:
		svm_write_tsc_offset(vcpu, data - native_read_tsc());
		break;
		}
		case MSR_STAR:
		svm->vmcb->save.star = data;
		break;

+5 −6

Original line number	Diff line number	Diff line
		@@ -1149,9 +1149,9 @@ static u64 guest_read_tsc(void)
		* writes 'guest_tsc' into guest's timestamp counter "register"
		* guest_tsc = host_tsc + tsc_offset ==> tsc_offset = guest_tsc - host_tsc
		*/
		static void guest_write_tsc(u64 guest_tsc, u64 host_tsc)
		static void vmx_write_tsc_offset(u64 offset)
		{
		vmcs_write64(TSC_OFFSET, guest_tsc - host_tsc);
		vmcs_write64(TSC_OFFSET, offset);
		}

		/*
		@@ -1255,7 +1255,7 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data)
		break;
		case MSR_IA32_TSC:
		rdtscll(host_tsc);
		guest_write_tsc(data, host_tsc);
		vmx_write_tsc_offset(data - host_tsc);
		break;
		case MSR_IA32_CR_PAT:
		if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT) {
		@@ -2512,7 +2512,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
		{
		u32 host_sysenter_cs, msr_low, msr_high;
		u32 junk;
		u64 host_pat, tsc_this;
		u64 host_pat;
		unsigned long a;
		struct desc_ptr dt;
		int i;
		@@ -2653,8 +2653,7 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx)
		vmx->vcpu.arch.cr4_guest_owned_bits \|= X86_CR4_PGE;
		vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits);

		tsc_this = native_read_tsc();
		guest_write_tsc(0, tsc_this);
		vmx_write_tsc_offset(0-native_read_tsc());

		return 0;
		}