[PATCH] KVM: selftests: Slightly simplify memstress_setup_nested()

[PATCH] KVM: selftests: Slightly simplify memstress_setup_nested()

[Yosry Ahmed]

Instead of calling memstress_setup_ept_mappings() only in the first
iteration in the loop, move it before the loop.

The call needed to happen within the loop before commit e40e72fec0de
("KVM: selftests: Stop passing VMX metadata to TDP mapping functions"),
as memstress_setup_ept_mappings() used to take in a pointer to vmx_pages
and pass it into tdp_identity_map_1g() (to get the EPT root GPA). This
is no longer the case, as tdp_identity_map_1g() gets the EPT root
through stage2 MMU.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
---
 tools/testing/selftests/kvm/lib/x86/memstress.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/x86/memstress.c b/tools/testing/selftests/kvm/lib/x86/memstress.c
index 86f4c5e4c430..f53414ba7103 100644
--- a/tools/testing/selftests/kvm/lib/x86/memstress.c
+++ b/tools/testing/selftests/kvm/lib/x86/memstress.c
@@ -110,16 +110,13 @@ void memstress_setup_nested(struct kvm_vm *vm, int nr_vcpus, struct kvm_vcpu *vc
 	TEST_REQUIRE(kvm_cpu_has_tdp());
 
 	vm_enable_tdp(vm);
+	memstress_setup_ept_mappings(vm);
 	for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) {
 		if (kvm_cpu_has(X86_FEATURE_VMX))
 			vcpu_alloc_vmx(vm, &nested_gva);
 		else
 			vcpu_alloc_svm(vm, &nested_gva);
 
-		/* The EPTs are shared across vCPUs, setup the mappings once */
-		if (vcpu_id == 0)
-			memstress_setup_ept_mappings(vm);
-
 		/*
 		 * Override the vCPU to run memstress_l1_guest_code() which will
 		 * bounce it into L2 before calling memstress_guest_code().

base-commit: f62b64b970570c92fe22503b0cdc65be7ce7fc7c
-- 
2.52.0.457.g6b5491de43-goog

Re: [PATCH] KVM: selftests: Slightly simplify memstress_setup_nested()

[Sean Christopherson]

On Tue, 13 Jan 2026 17:14:56 +0000, Yosry Ahmed wrote:
> Instead of calling memstress_setup_ept_mappings() only in the first
> iteration in the loop, move it before the loop.
> 
> The call needed to happen within the loop before commit e40e72fec0de
> ("KVM: selftests: Stop passing VMX metadata to TDP mapping functions"),
> as memstress_setup_ept_mappings() used to take in a pointer to vmx_pages
> and pass it into tdp_identity_map_1g() (to get the EPT root GPA). This
> is no longer the case, as tdp_identity_map_1g() gets the EPT root
> through stage2 MMU.
> 
> [...]

Applied to kvm-x86 selftests, thanks!

[1/1] KVM: selftests: Slightly simplify memstress_setup_nested()
      https://github.com/kvm-x86/linux/commit/f756ed82c62a

--
https://github.com/kvm-x86/linux/tree/next