From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) (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 BB0D62472AE for ; Fri, 4 Sep 2026 00:24:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788481475; cv=none; b=BLgW7HvFs6ntoTspXx1MrjhmNOFXhE7qJAEzsEPopGinzf2UCqVGBa7h7F/YRXMz5Dkz+gCCt14bYZnx++1gERaWTiO/jVG4wMR2haVtmY/NQ62d0oVWXslxs++Gc1osyssMNK0wcjzsp6cdx3EBtUr0p6HbtsSg2u94DhemLwQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788481475; c=relaxed/simple; bh=Q7qpdWJEFs8lqslQBXctE4tqpv3fzC5rKtHXZQkZOvU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BLJc1IjVbdZj/rqKKTPGUzAZ2DQzftoqZv7kET5QT2rvkf4hD50+vc/bo7YRkcmwftaZooCadxqdbprSUA4eTBT430EJ8aCmNeLRpx5RNW8bs4plfKivGTXpxinxCc7e/U1ZbwkQH7aFXN5ffleWcZhEG+1HabmPmpBqg0G0IFQ= 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=CTENJn+L; arc=none smtp.client-ip=209.85.210.197 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="CTENJn+L" Received: by mail-pf1-f197.google.com with SMTP id d2e1a72fcca58-84e024d2129so614557b3a.2 for ; Thu, 03 Sep 2026 17:24:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788481472; x=1789086272; 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=wRWK/v12x99rpq8aWGzvGBtRUnaxTCM6WoKg5BCcAo4=; b=CTENJn+LUSpcW2lMtC+wi/5eqSiZr24HUZeKn8ulmXsUdBdh8GovS8IBXqKF2qrGau wY/kzWCIantR8mD8sRTGWZibnBC2ZW5ClaMuZahaQhgpMPOEgHkmU1q4OJFudfTqwit6 vAmu/6nOQFguPTlqXywCtrGnE5ZYYM001BK0jqYZuiS2hf3QiMYEri55aEeRV1ygdx7d A8PFws/4c7TDauqaM3Nzhy5fsVQCnwHh0a8vTocdKwIrH0YSLr4ejNcmASbYzNuR8cGM rgSbe2W4MdX47Yu8baFiTXZpWVPcgQMGVIqMQzIdKbIA6iuwvpFkbt4rNUBkgsuo9irz jP9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788481472; x=1789086272; 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=wRWK/v12x99rpq8aWGzvGBtRUnaxTCM6WoKg5BCcAo4=; b=B9ZjAbMaqZi5fDqgPNOL8drzFiMXSDfzCC4G8f5Gt0lgZH5/5DSrvLqahl78l26UYh 68jxoY24saMZUAa0XbTRPliZ3vb0fZtC2Yp0Lkb1b9FkWZCxrOOoPqCi7erHPHBDqitI Lcahtc0mo1kjP94JWGE0EVmBDPo+xDSwdVSzhpdtL8tBj2npWbdn1UaYtJ/Bu2cCp9zQ PqSDwLuEJ4tol/RyrD1h43WueWskaDdF+oL9QmnwcabkZl6BQT4WwWfODEorD26AfbMP Qp5TfFlmdtshFbw57rFD2TLwv7wFgfst4RM7Gz+lnT71P3O8MYNM4rGcR3c194tN7/rY u0FA== X-Gm-Message-State: AFuF++lgsLxLWgmwcKcUqXo+lCFC80oY9ULC/snO2yyQlLllakWzzdGZ ibp3tbjhyICFkHevy67MfZizw8SN23w0wPXE4jKw1Ru6kG6gzTiFsSBkHNp26cIGwvLigd8EjIx i4H26eQ== X-Received: from pfus9.prod.google.com ([2002:a05:6a00:8c9:b0:847:ac08:fdf6]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:4b4c:b0:85c:9bb4:a7ea with SMTP id d2e1a72fcca58-8616af56c5fmr2991883b3a.11.1788481471741; Thu, 03 Sep 2026 17:24:31 -0700 (PDT) Reply-To: Sean Christopherson Date: Thu, 3 Sep 2026 17:24:11 -0700 In-Reply-To: <20260904002423.3154436-1-seanjc@google.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260904002423.3154436-1-seanjc@google.com> X-Mailer: git-send-email 2.55.0.979.g7e5102b832-goog Message-ID: <20260904002423.3154436-6-seanjc@google.com> Subject: [PATCH v4 05/17] 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: -- 2.55.0.979.g7e5102b832-goog