From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EA3A377567; Tue, 12 May 2026 01:40:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778550043; cv=none; b=bob4StwDcEdynqbZGyehtH1uY3kVCQ0iOvc+KQXDOm04z8OhU35n6lUkb/cTyEh/pcf1kBXcYCKrZegKVccuuEqKKbAUhWn4axhJjW/3ik0n/eC9WwldLBEKTP7AIUn/hiS76qWr5idqbhE2MnxloQZs/8dizQ3qlU0hYqr5Il8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778550043; c=relaxed/simple; bh=kDBtMaYWjk5NvmUllhFtCoGexQHRWExwMpcbE6sdArs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AyF5k+LdxP1Gl2owfUoxNNYBzOFEioFXMbOiAVevZBehAhQn73/SwZFn3VrY7+yyRpDZlr0FFaMwg9EFa3tzDtcrqBZGIGL1m+nKDLDcu4rDDDKR98iGjvU51MJzAZz418fDSoImIV3yHJ2brAzyIkpsO8v3ntSQOzF32hO+1R8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=MDsawDBx; arc=none smtp.client-ip=198.175.65.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="MDsawDBx" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1778550042; x=1810086042; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=kDBtMaYWjk5NvmUllhFtCoGexQHRWExwMpcbE6sdArs=; b=MDsawDBxxtFJVAQXtMbC0tjsVxwWQQHv02jb+D10+XJneBUWU2WSPPTe KlRMSTBvulMj1ZckebH30Uqugg5LPLyxGyISmUiP+MqVPDxBl2RZ72Pn6 ufjH0lwZYOCe++4YySkpMyrPLVkOZfEGsatvOJz8lx93tZ7hb7EzKp9cu OuH/DyqFnAx4dBAwqD7IAjL8ID4PgMcTaZ7ex5cYYNU7ufDBGvQlfhVud 60moEXEteUwJUChvsJOAIZisfskYESD0acGi97+ZG+kDYtKMqHHVKa6P6 FoEgM9zCu0puU2h3GdtdTxmY+Ln3jy/5vvUJMdff5kM9iJgnf7SyQDK1C Q==; X-CSE-ConnectionGUID: 0QMAGANoT9GDK7EUafuECg== X-CSE-MsgGUID: pS2XXzEETfSZVc1k7yOVMQ== X-IronPort-AV: E=McAfee;i="6800,10657,11783"; a="83322203" X-IronPort-AV: E=Sophos;i="6.23,230,1770624000"; d="scan'208";a="83322203" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 May 2026 18:40:34 -0700 X-CSE-ConnectionGUID: dEJbdrG1TiGEoLvKFLLgQw== X-CSE-MsgGUID: 0yFJeiXCSmOuwkOWyUiqWQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,230,1770624000"; d="scan'208";a="234572843" Received: from chang-linux-3.sc.intel.com (HELO chang-linux-3) ([172.25.66.106]) by fmviesa007.fm.intel.com with ESMTP; 11 May 2026 18:40:34 -0700 From: "Chang S. Bae" To: pbonzini@redhat.com, seanjc@google.com Cc: kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, chao.gao@intel.com, chang.seok.bae@intel.com Subject: [PATCH v4 21/21] KVM: x86: selftests: Add APX state handling and XCR0 sanity checks Date: Tue, 12 May 2026 01:15:02 +0000 Message-ID: <20260512011502.53072-22-chang.seok.bae@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260512011502.53072-1-chang.seok.bae@intel.com> References: <20260512011502.53072-1-chang.seok.bae@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Now that KVM exposes the APX feature to guests, extend some existing selftests to validate XCR0 configuration and state management. Since APX repurposes the XSAVE area previously used by MPX in the non-compacted format, add a check to ensure that MPX states are not set when APX is enabled. Also, load non-init APX state data in the guest so that XSTATE_BV[APX] is set, allowing validation of APX state testing. Signed-off-by: Chang S. Bae --- tools/testing/selftests/kvm/x86/state_test.c | 3 +++ .../selftests/kvm/x86/xcr0_cpuid_test.c | 19 +++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/tools/testing/selftests/kvm/x86/state_test.c b/tools/testing/selftests/kvm/x86/state_test.c index 409c6cc9f921..7d93d62fc6a5 100644 --- a/tools/testing/selftests/kvm/x86/state_test.c +++ b/tools/testing/selftests/kvm/x86/state_test.c @@ -171,6 +171,9 @@ static void __attribute__((__flatten__)) guest_code(void *arg) asm volatile ("vmovupd %0, %%zmm16" :: "m" (buffer)); } + if (supported_xcr0 & XFEATURE_MASK_APX) + write_egpr(16, 0xcccccccc); + if (this_cpu_has(X86_FEATURE_MPX)) { u64 bounds[2] = { 10, 0xffffffffull }; u64 output[2] = { }; diff --git a/tools/testing/selftests/kvm/x86/xcr0_cpuid_test.c b/tools/testing/selftests/kvm/x86/xcr0_cpuid_test.c index 40dc9e6b3fad..f74978ef5951 100644 --- a/tools/testing/selftests/kvm/x86/xcr0_cpuid_test.c +++ b/tools/testing/selftests/kvm/x86/xcr0_cpuid_test.c @@ -46,6 +46,20 @@ do { \ __supported, (xfeatures)); \ } while (0) +/* + * Verify that mutually exclusive architectural features do not overlap. + * For example, APX and MPX must never be reported as supported together. + */ +#define ASSERT_XFEATURE_CONFLICT(supported_xcr0, xfeatures, conflicts) \ +do { \ + uint64_t __supported = (supported_xcr0) & ((xfeatures) | (conflicts)); \ + \ + __GUEST_ASSERT((__supported & (xfeatures)) != (xfeatures) || \ + !(__supported & (conflicts)), \ + "supported = 0x%lx, xfeatures = 0x%llx, conflicts = 0x%llx", \ + __supported, (xfeatures), (conflicts)); \ +} while (0) + static void guest_code(void) { u64 initial_xcr0; @@ -79,6 +93,11 @@ static void guest_code(void) ASSERT_ALL_OR_NONE_XFEATURE(supported_xcr0, XFEATURE_MASK_XTILE); + /* Check APX by ensuring MPX is not exposed concurrently */ + ASSERT_XFEATURE_CONFLICT(supported_xcr0, + XFEATURE_MASK_APX, + XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); + vector = xsetbv_safe(0, XFEATURE_MASK_FP); __GUEST_ASSERT(!vector, "Expected success on XSETBV(FP), got %s", -- 2.51.0