Commit 462f092d authored by Sean Christopherson's avatar Sean Christopherson
Browse files

KVM: VMX: Drop intermediate "guest" field from msr_autostore 



Drop the intermediate "guest" field from vcpu_vmx.msr_autostore as the
value saved on VM-Exit isn't guaranteed to be the guest's value, it's
purely whatever is in hardware at the time of VM-Exit.  E.g. KVM's only
use of the store list at the momemnt is to snapshot TSC at VM-Exit, and
the value saved is always the raw TSC even if TSC-offseting and/or
TSC-scaling is enabled for the guest.

And unlike msr_autoload, there is no need differentiate between "on-entry"
and "on-exit".

No functional change intended.

Cc: Jim Mattson <jmattson@google.com>
Reviewed-by: default avatarDapeng Mi <dapeng1.mi@linux.intel.com>
Tested-by: default avatarManali Shukla <manali.shukla@amd.com>
Link: https://patch.msgid.link/20251206001720.468579-36-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent b0b6a8d3

arch/x86/kvm/vmx/nested.c

+5 −5
Original line number Diff line number Diff line
@@ -1076,11 +1076,11 @@ static bool nested_vmx_get_vmexit_msr_value(struct kvm_vcpu *vcpu, 
	 * VM-exit in L0, use the more accurate value.

	 */

	if (msr_index == MSR_IA32_TSC) {

		int i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore.guest,

		int i = vmx_find_loadstore_msr_slot(&vmx->msr_autostore,

						    MSR_IA32_TSC);



		if (i >= 0) {

			u64 val = vmx->msr_autostore.guest.val[i].value;

			u64 val = vmx->msr_autostore.val[i].value;



			*data = kvm_read_l1_tsc(vcpu, val);

			return true;
@@ -1167,7 +1167,7 @@ static void prepare_vmx_msr_autostore_list(struct kvm_vcpu *vcpu, 
					   u32 msr_index)

{

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	struct vmx_msrs *autostore = &vmx->msr_autostore.guest;

	struct vmx_msrs *autostore = &vmx->msr_autostore;

	bool in_vmcs12_store_list;

	int msr_autostore_slot;

	bool in_autostore_list;
@@ -2366,7 +2366,7 @@ static void prepare_vmcs02_constant_state(struct vcpu_vmx *vmx) 
	 * addresses are constant (for vmcs02), the counts can change based

	 * on L2's behavior, e.g. switching to/from long mode.

	 */

	vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autostore.guest.val));

	vmcs_write64(VM_EXIT_MSR_STORE_ADDR, __pa(vmx->msr_autostore.val));

	vmcs_write64(VM_EXIT_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.host.val));

	vmcs_write64(VM_ENTRY_MSR_LOAD_ADDR, __pa(vmx->msr_autoload.guest.val));
@@ -2704,7 +2704,7 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) 
	 */

	prepare_vmx_msr_autostore_list(&vmx->vcpu, MSR_IA32_TSC);



	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.guest.nr);

	vmcs_write32(VM_EXIT_MSR_STORE_COUNT, vmx->msr_autostore.nr);

	vmcs_write32(VM_EXIT_MSR_LOAD_COUNT, vmx->msr_autoload.host.nr);

	vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr);

arch/x86/kvm/vmx/vmx.c

+1 −1
Original line number Diff line number Diff line
@@ -6567,7 +6567,7 @@ void dump_vmcs(struct kvm_vcpu *vcpu) 
	if (vmcs_read32(VM_ENTRY_MSR_LOAD_COUNT) > 0)

		vmx_dump_msrs("guest autoload", &vmx->msr_autoload.guest);

	if (vmcs_read32(VM_EXIT_MSR_STORE_COUNT) > 0)

		vmx_dump_msrs("guest autostore", &vmx->msr_autostore.guest);

		vmx_dump_msrs("autostore", &vmx->msr_autostore);



	if (vmentry_ctl & VM_ENTRY_LOAD_CET_STATE)

		pr_err("S_CET = 0x%016lx, SSP = 0x%016lx, SSP TABLE = 0x%016lx\n",

arch/x86/kvm/vmx/vmx.h

+1 −3
Original line number Diff line number Diff line
@@ -245,9 +245,7 @@ struct vcpu_vmx { 
		struct vmx_msrs host;

	} msr_autoload;



	struct msr_autostore {

		struct vmx_msrs guest;

	} msr_autostore;

	struct vmx_msrs msr_autostore;



	struct {

		int vm86_active;