From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f198.google.com (mail-pf1-f198.google.com [209.85.210.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5FE33C09F9 for ; Wed, 26 Aug 2026 23:39:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787787571; cv=none; b=GpRpZsroJ91SPb7dV0Yyrh4yDXIonkxhaKprtWvzyWI/OR47+Jc51dMZBBwKSx8mPnKIqzm8BjSc0grmiTLwKlv8RWM6xV3nl0YHCkUen4BzNTeqWtwZ2WvV+6tlocfL9X9OAMEAKA6AzDZX2Wk/sMzPYFOmnVmclyLTrDBQVFQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787787571; c=relaxed/simple; bh=PaH7v/6ZshYM/7JV06k//ebWoKkZhJSEyltBWJM+apc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=UMgiHUPqc8B3IDB44Mr+ZGO5zg7r0SBOP7beHcsrNKjXNrJmXznkPr0gecK73ts/QQaFijNMTaBblBUcv632m3e30gqE3z8tlL7LBlpD3BkpQHkRMjf8IwMVdgFH5w8EAxUvA2EvekTERB9ODGl0MHlG/tga163Rm8n/HMr69ko= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Fv7b2hj3; arc=none smtp.client-ip=209.85.210.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Fv7b2hj3" Received: by mail-pf1-f198.google.com with SMTP id d2e1a72fcca58-854f274dd69so268094b3a.1 for ; Wed, 26 Aug 2026 16:39:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1787787567; x=1788392367; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:from:to:cc:subject:date:message-id :reply-to:content-type; bh=rnnRN8hJfQwgolvTmyTrKWAk5xBd0sRsJp37TMVzJVc=; b=Fv7b2hj3WeDf/KiMfk4K8EIXktD2XA6j/UXo4nzaT0R6kbX7ybwdDL/s4v5g+vrJVw WO+noAJuO7Zk2pubqQKIyhAVPUiQGA7ih0I88kylAL8REQJAc//Uo6zLqL9vrAA1n098 RfjDKmlYyb36bc+7ddVu2V1wGBDZLGRxxPfxnLWXB5HvBFYOfAUovHP/qn1SwoB5M6ek m9RCb/6j6yLQvETBvJPi0lyjWzdegVDNfJrnMZ/kAvft5jAIo7XyMJmLWEh6g98kbvsH b7pKGfB4n/1ysjWc07U90q7srEzdHmHxMGNILUq9e1LOhelGqzx5aycK0PjjJFeCKdCh 60sg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787787567; x=1788392367; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:reply-to:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to:content-type; bh=rnnRN8hJfQwgolvTmyTrKWAk5xBd0sRsJp37TMVzJVc=; b=PJd7h69QUN7LFWmZm2Wz1rG6Hd6g3ICsiYtEam16xL2dt31oqgQvNgX8Jv1/MgiVnH xKi2OcrU8TtjM46YEkPUOQ+pKhPIniJ9z2EvSvzpz0KM99BrKo/KVps6A0tAoFe/pKLE 6P8DWozomParjLJJ8jn5Q7jo6LshJrc+CvmZy402BRtPHneUK4UEe/cX15Lz9SQ8DLUo 59p+JLF3CqFLwh5809xGkwD8Z8FfNbhqOjthgJsaXCvaOM9HEOcgM5WljeDcEjikEfqQ y5MAbjQrg3pEJ4cYnVq7QU+HLJ2CARVemXW3fJ1IZ6+zictgUyZRWhk9P3yMx0K75Fio 02QA== X-Forwarded-Encrypted: i=1; AHgh+RpkTgEzJPflsJFeyUgQBDdxfedU4oSqwzNXv2xsEZtvkh0OIjsNBaF79uuDQMzvlos367o7DERslsuTufA=@vger.kernel.org X-Gm-Message-State: AFuF++nr5HyqvrdqidHGDKTHhTCx5+P4ghFnVK3trQJ1WqCVHFY/pejl y/tvMGcRKSngp4oBwY0pUO4YyvKB6BGVPjIFNMg3u0qDN0RafzHSkSxqGkyW7YGH68ivhzuOKzh 3j6vIfw== X-Received: from pgco21.prod.google.com ([2002:a63:7315:0:b0:cc1:bf49:dfd2]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:1a12:b0:854:9b2a:f898 with SMTP id d2e1a72fcca58-8549b2af9f9mr7835471b3a.8.1787787567089; Wed, 26 Aug 2026 16:39:27 -0700 (PDT) Reply-To: Sean Christopherson Date: Wed, 26 Aug 2026 16:39:11 -0700 In-Reply-To: <20260826233919.998904-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260826233919.998904-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.887.g758fc8c411-goog Message-ID: <20260826233919.998904-6-seanjc@google.com> Subject: [PATCH v3 05/13] KVM: selftests: Check VMPTRLD with active eVMCS From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, f734222792@gmail.com, Vitaly Kuznetsov , Sashiko Bot , Yosry Ahmed Content-Type: text/plain; charset="UTF-8" From: Vitaly Kuznetsov Check that VMPTRLD when eVMCS is active results in #UD. This matches genuine Hyper-V's behavior. Use KVM_ASM_SAFE framework to handle #UD from VMPTRLD. Unfortunately, the same trick cannot be applied to the existing #UD check on VMLAUNCH as VMLAUNCH clobbers all registers which KVM_ASM_SAFE depends on. Keep VMLAUNCH handling separately. Deliberately use a double-underscores prefix instead of a "safe" postfix for the helper, to communicate that the inner/outer helpers handle more than just exceptions, they also handle VM-Fail conditions. Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Vitaly Kuznetsov [sean: use __ instead of _safe] Signed-off-by: Sean Christopherson --- tools/testing/selftests/kvm/include/x86/vmx.h | 19 +++++++++++--- .../testing/selftests/kvm/x86/hyperv_evmcs.c | 26 +++++++++++++++---- 2 files changed, 37 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86/vmx.h b/tools/testing/selftests/kvm/include/x86/vmx.h index ac7d48d1387e..a161dbee7e04 100644 --- a/tools/testing/selftests/kvm/include/x86/vmx.h +++ b/tools/testing/selftests/kvm/include/x86/vmx.h @@ -342,9 +342,6 @@ 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) @@ -353,6 +350,22 @@ static inline int vmptrld(u64 vmcs_pa) return ret; } +static inline int __vmptrld(u64 vmcs_pa) +{ + u64 error_code; + u8 vector; + u8 failed; + + asm volatile(KVM_ASM_SAFE("vmptrld %[pa]") + "\n\tsetna %[failed]" + : KVM_ASM_SAFE_OUTPUTS(vector, error_code), + [failed]"=qm"(failed) + : [pa]"m"(vmcs_pa) + : "cc", "memory", KVM_ASM_SAFE_CLOBBERS); + + return vector ? vector : failed ? -EINVAL : 0; +} + static inline int vmptrst(u64 *value) { u64 tmp; diff --git a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c index 6224d859d7bb..f953a9755a76 100644 --- a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c +++ b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c @@ -23,7 +23,11 @@ static int ud_count; static void guest_ud_handler(struct ex_regs *regs) { ud_count++; - regs->rip += 3; /* VMLAUNCH */ + /* + * VMLAUNCH insn can't be easily covered by KVM_ASM_SAFE framework but + * luckily the instruction is always three bytes. + */ + regs->rip += 3; } static void guest_nmi_handler(struct ex_regs *regs) @@ -178,7 +182,15 @@ 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); - /* Try enlightened vmptrld with an incorrect GPA */ + /* VMPTRLD instruction causes #UD after enlightened VMLAUNCH */ + GUEST_ASSERT(__vmptrld(hv_pages->enlightened_vmcs_gpa) == UD_VECTOR); + + /* + * Try enlightened vmptrld with an incorrect GPA. GUEST_SYNC(12) signals + * the host to enable guest_ud_handler() which cannot be enabled beforehand + * to not override the default fixup handler from KVM_ASM_SAFE(). + */ + GUEST_SYNC(12); evmcs_vmptrld(0xdeadbeef, hv_pages->enlightened_vmcs); GUEST_ASSERT(vmlaunch()); GUEST_ASSERT(ud_count == 1); @@ -252,7 +264,6 @@ int main(int argc, char *argv[]) vcpu_args_set(vcpu, 3, vmx_pages_gva, hv_pages_gva, addr_gva2gpa(vm, hcall_page)); vcpu_set_msr(vcpu, HV_X64_MSR_VP_INDEX, vcpu->id); - vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler); vm_install_exception_handler(vm, NMI_VECTOR, guest_nmi_handler); pr_info("Running L1 which uses EVMCS to run L2\n"); @@ -282,7 +293,7 @@ int main(int argc, char *argv[]) /* Force immediate L2->L1 exit before resuming */ if (stage == 8) { - pr_info("Injecting NMI into L1 before L2 had a chance to run after restore\n"); + pr_debug("Injecting NMI into L1 before L2 had a chance to run after restore\n"); inject_nmi(vcpu); } @@ -292,9 +303,14 @@ int main(int argc, char *argv[]) * KVM_STATE_NESTED_EVMCS is not lost. */ if (stage == 9) { - pr_info("Trying extra KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE cycle\n"); + pr_debug("Trying extra KVM_GET_NESTED_STATE/KVM_SET_NESTED_STATE cycle\n"); vcpu = save_restore_vm(vm, vcpu); } + + if (stage == 12) { + pr_debug("Trying enlightened VMLAUNCH with an invalid PTR\n"); + vm_install_exception_handler(vm, UD_VECTOR, guest_ud_handler); + } } done: -- 2.55.0.887.g758fc8c411-goog