Kernel KVM virtualization development
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From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org, Sean Christopherson <seanjc@google.com>,
	Paolo Bonzini <pbonzini@redhat.com>
Cc: f734222792@gmail.com, linux-kernel@vger.kernel.org
Subject: [PATCH 4/4] KVM: selftests: Check VMPTRLD with active eVMCS
Date: Fri, 14 Aug 2026 18:22:21 +0200	[thread overview]
Message-ID: <20260814162221.2144473-5-vkuznets@redhat.com> (raw)
In-Reply-To: <20260814162221.2144473-1-vkuznets@redhat.com>

Check that VMPTRLD when eVMCS is active results in #UD. This matches
genuine Hyper-V's behavior.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
 tools/testing/selftests/kvm/include/x86/vmx.h  |  3 ---
 tools/testing/selftests/kvm/x86/hyperv_evmcs.c | 13 +++++++++++--
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/x86/vmx.h b/tools/testing/selftests/kvm/include/x86/vmx.h
index 047d02aa9688..e2178a6683ca 100644
--- a/tools/testing/selftests/kvm/include/x86/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86/vmx.h
@@ -325,9 +325,6 @@ static inline int vmptrld(u64 vmcs_pa)
 {
 	u8 ret;
 
-	if (enable_evmcs)
-		return -1;
-
 	__asm__ __volatile__ ("vmptrld %[pa]; setna %[ret]"
 		: [ret]"=rm"(ret)
 		: [pa]"m"(vmcs_pa)
diff --git a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
index 88262ddf7fcb..6a6d940a7891 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
@@ -18,12 +18,16 @@
 #include "hyperv.h"
 #include "vmx.h"
 
+#define VMLAUNCH_INSN_SIZE 3
+#define VMPTRLD_INSN_SIZE 5
+
 static int ud_count;
+static int ud_insn_skip_size;
 
 static void guest_ud_handler(struct ex_regs *regs)
 {
 	ud_count++;
-	regs->rip += 3; /* VMLAUNCH */
+	regs->rip += ud_insn_skip_size;
 }
 
 static void guest_nmi_handler(struct ex_regs *regs)
@@ -182,10 +186,15 @@ void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages,
 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
 	GUEST_SYNC(11);
 
+	ud_insn_skip_size = VMPTRLD_INSN_SIZE;
+	vmptrld(hv_pages->enlightened_vmcs_gpa);
+	GUEST_ASSERT(ud_count == 1);
+
 	/* Try enlightened vmptrld with an incorrect GPA */
+	ud_insn_skip_size = VMLAUNCH_INSN_SIZE;
 	evmcs_vmptrld(0xdeadbeef, hv_pages->enlightened_vmcs);
 	GUEST_ASSERT(vmlaunch());
-	GUEST_ASSERT(ud_count == 1);
+	GUEST_ASSERT(ud_count == 2);
 	GUEST_DONE();
 }
 
-- 
2.55.0


  parent reply	other threads:[~2026-08-14 16:22 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-14 16:22 [PATCH 0/4] KVM: nVMX: Adjust VMPTRLD/VMPTRST behavior with active eVMCS Vitaly Kuznetsov
2026-08-14 16:22 ` [PATCH 1/4] KVM: nVMX: Make VMPTRLD result in #UD when eVMCS is used Vitaly Kuznetsov
2026-08-14 16:31   ` sashiko-bot
2026-08-14 16:43     ` Sean Christopherson
2026-08-14 16:22 ` [PATCH 2/4] KVM: nVMX: Make VMPTRST return eVMCS GPA when it " Vitaly Kuznetsov
2026-08-14 16:32   ` sashiko-bot
2026-08-14 16:44     ` Sean Christopherson
2026-08-14 16:22 ` [PATCH 3/4] KVM: selftests: Adapt to the updated VMPTRST behavior when eVMCS " Vitaly Kuznetsov
2026-08-14 16:31   ` sashiko-bot
2026-08-14 16:22 ` Vitaly Kuznetsov [this message]
2026-08-14 16:31   ` [PATCH 4/4] KVM: selftests: Check VMPTRLD with active eVMCS sashiko-bot
2026-08-17 11:26     ` Vitaly Kuznetsov
2026-08-17 17:06       ` Sean Christopherson

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