[PATCH v3 09/26] KVM: nSVM: Make nested_svm_merge_msrpm() return an errno

From: Yosry Ahmed

Date: Mon Dec 15 2025 - 14:28:39 EST


In preparation for moving nested_svm_merge_msrpm() within
enter_svm_guest_mode(), which returns an errno, return an errno from
nested_svm_merge_msrpm().

No functional change intended.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 384352365310..f46e97008492 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -261,7 +261,7 @@ int __init nested_svm_init_msrpm_merge_offsets(void)
* is optimized in that it only merges the parts where KVM MSR permission bitmap
* may contain zero bits.
*/
-static bool nested_svm_merge_msrpm(struct kvm_vcpu *vcpu)
+static int nested_svm_merge_msrpm(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
nsvm_msrpm_merge_t *msrpm02 = svm->nested.msrpm;
@@ -288,17 +288,19 @@ static bool nested_svm_merge_msrpm(struct kvm_vcpu *vcpu)
#endif

if (!(vmcb12_is_intercept(&svm->nested.ctl, INTERCEPT_MSR_PROT)))
- return true;
+ return 0;

for (i = 0; i < nested_svm_nr_msrpm_merge_offsets; i++) {
const int p = nested_svm_msrpm_merge_offsets[i];
nsvm_msrpm_merge_t l1_val;
gpa_t gpa;
+ int r;

gpa = svm->nested.ctl.msrpm_base_pa + (p * sizeof(l1_val));

- if (kvm_vcpu_read_guest(vcpu, gpa, &l1_val, sizeof(l1_val)))
- return false;
+ r = kvm_vcpu_read_guest(vcpu, gpa, &l1_val, sizeof(l1_val));
+ if (r)
+ return r;

msrpm02[p] = msrpm01[p] | l1_val;
}
@@ -310,7 +312,7 @@ static bool nested_svm_merge_msrpm(struct kvm_vcpu *vcpu)
#endif
svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));

- return true;
+ return 0;
}

/*
@@ -991,7 +993,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu)
if (enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, true))
goto out_exit_err;

- if (nested_svm_merge_msrpm(vcpu))
+ if (!nested_svm_merge_msrpm(vcpu))
goto out;

out_exit_err:
@@ -1887,7 +1889,7 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
if (CC(!load_pdptrs(vcpu, vcpu->arch.cr3)))
return false;

- if (!nested_svm_merge_msrpm(vcpu)) {
+ if (nested_svm_merge_msrpm(vcpu)) {
vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
vcpu->run->internal.suberror =
KVM_INTERNAL_ERROR_EMULATION;
--
2.52.0.239.gd5f0c6e74e-goog