[PATCH v3 2/3] KVM: SVM: remove uneeded fields from host_save_users_msrs

From: Michael Roth
Date: Tue Jan 05 2021 - 09:40:33 EST


Now that the set of host user MSRs that need to be individually
saved/restored are the same with/without SEV-ES, we can drop the
.sev_es_restored flag and just iterate through the list unconditionally
for both cases. A subsequent patch can then move these loops to a
common path.

Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
---
arch/x86/kvm/svm/sev.c | 16 ++++------------
arch/x86/kvm/svm/svm.c | 6 ++----
arch/x86/kvm/svm/svm.h | 7 ++-----
3 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index e57847ff8bd2..2a93b63322f4 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2007,12 +2007,8 @@ void sev_es_vcpu_load(struct vcpu_svm *svm, int cpu)
* Certain MSRs are restored on VMEXIT, only save ones that aren't
* restored.
*/
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) {
- if (host_save_user_msrs[i].sev_es_restored)
- continue;
-
- rdmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]);
- }
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
+ rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);

/* XCR0 is restored on VMEXIT, save the current host value */
hostsa = (struct vmcb_save_area *)(page_address(sd->save_area) + 0x400);
@@ -2033,10 +2029,6 @@ void sev_es_vcpu_put(struct vcpu_svm *svm)
* Certain MSRs are restored on VMEXIT and were saved with vmsave in
* sev_es_vcpu_load() above. Only restore ones that weren't.
*/
- for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++) {
- if (host_save_user_msrs[i].sev_es_restored)
- continue;
-
- wrmsrl(host_save_user_msrs[i].index, svm->host_user_msrs[i]);
- }
+ for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
+ wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 7a7e9b7d47a7..7e1b5b452244 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1421,8 +1421,7 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
sev_es_vcpu_load(svm, cpu);
} else {
for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- rdmsrl(host_save_user_msrs[i].index,
- svm->host_user_msrs[i]);
+ rdmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);

asm volatile(__ex("vmsave %%"_ASM_AX)
: : "a" (page_to_phys(sd->save_area)) : "memory");
@@ -1458,8 +1457,7 @@ static void svm_vcpu_put(struct kvm_vcpu *vcpu)
sev_es_vcpu_put(svm);
} else {
for (i = 0; i < NR_HOST_SAVE_USER_MSRS; i++)
- wrmsrl(host_save_user_msrs[i].index,
- svm->host_user_msrs[i]);
+ wrmsrl(host_save_user_msrs[i], svm->host_user_msrs[i]);
}
}

diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 1f4460508036..a476449862f8 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -23,11 +23,8 @@

#define __sme_page_pa(x) __sme_set(page_to_pfn(x) << PAGE_SHIFT)

-static const struct svm_host_save_msrs {
- u32 index; /* Index of the MSR */
- bool sev_es_restored; /* True if MSR is restored on SEV-ES VMEXIT */
-} host_save_user_msrs[] = {
- { .index = MSR_TSC_AUX, .sev_es_restored = false },
+static const u32 host_save_user_msrs[] = {
+ MSR_TSC_AUX,
};
#define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs)

--
2.25.1