From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (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 80F5E3246E8 for ; Thu, 7 May 2026 20:34:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778186080; cv=none; b=G7X7OWL1h/0rpzqZEGb7Vek9XzgA4j7adfAtzo17sCo2IgwCdmDxlGubo6iIpNDhumZJ9ZLWGkUhc9+AvIqL460wfiOE0YJm2bnvmLfmJvxD7D6/4jjICrVtw+VAqloqqFaLkrTyz+PmAqzBkgmvENbKM9rWOi8BD0KEHjWP+hc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778186080; c=relaxed/simple; bh=GOjFoV94awk7GYninYEq+I3DCtzIDlhYvlgo8SkP+9g=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=N787zwr/yEhGSKMtxxHXsl8q+xk4aFKXTYVjQoKhPccfDOl/MKUav6wmVSfX2FRAEMGBDCGJHn1N5x187ycRhQwbCUQeszVEtjPpjy/GSpN2fK/qwsV6cYK99/aJBuYGvNUgvCGxR1XN1ro9WSUZBBpZgbC9TItlyaHUX6oTFbs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--ackerleytng.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=axqqEJNO; arc=none smtp.client-ip=209.85.216.73 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--ackerleytng.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="axqqEJNO" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-3650a4eb60dso1376053a91.1 for ; Thu, 07 May 2026 13:34:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1778186077; x=1778790877; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=FwdqijLGyLJ4WnaXvFgo9eGiQSeu4QsrqPYNc8/yMrg=; b=axqqEJNOhE9jSDrsvB/sNgxY5KKC7KwPN6q783aLHD0TZNub06H4qJSO03mHEcbnxM MYHI25A/3eg+g4vl4SRV/wy/Qiyp1XNnpif/fH5OKjoxr6gT0Le7BCovUQCaq0j7w3yS 0oT1TLZ8orfGWrQlJ3o5QEo2spJN5y4AmjZ2oxHPh31ypSiDoIyr0/KkLRnPDMp61pJd +zIQfnn+YHutgtgDCv/PPeecKQkaetXfIhYw/xqXq5P0A+n/FLr/x/7xNtOR7Wa0I4i3 MIaw4MAN50Yu2x17+dV2+oU6NsSBd4xK/SpLy0NSBBw72GEDUIxTM3wsE0hvJLmLTWcp ezEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778186077; x=1778790877; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=FwdqijLGyLJ4WnaXvFgo9eGiQSeu4QsrqPYNc8/yMrg=; b=Y8KrkaoawRJl2q1bFA5nIzCeVBoZXayGS2y6Wr7ZsnFTZ5LaWjPctYOAFixfrXJSA9 JrLTzcg97fZPgxdDvFM5Mk+iFActd+WZrrKgFpYgTp+sLimb28CHRgChEnznz/C2kXum GaqBdlWVOvW/4Ux4h1/W+RQGfHMjKZiZTcwXhVM1fS+8x/akhoz91swqZIcA8rWLSeW1 EIb/lMDsrHaX5ez9ytZursxEFDQF1B/vEwgTVHr8AWtIxuSmYsdMsjsgsncQgZy5I5Gi AvslaK1IF396yQVgEyG63v7VXKXC/HpJxzwxx1BByWE4UvHjzFk3SnvioOMEoqL5tLAf EMug== X-Forwarded-Encrypted: i=1; AFNElJ+X4SyTcGS4eNPkIShDqffAk+TUD8VDooVM2BJw2qPTxChfN1ydPbdtC13a6v2RQbANUs3qC05v+kI=@vger.kernel.org X-Gm-Message-State: AOJu0YycniONu6Rgs9xEUw0+aKVbeO0QGAUUhtHtiUvpSgvYe2Mj9UO9 oSGdi6VJtnDnhviZbJNekebn2VS9T62O4XE+6OHAAASB44lo0VunYEvrdML/JgUmUe8uERQrehw KxeuPzog6MQJ6UWuFaCt3sY8vbQ== X-Received: from pgac15.prod.google.com ([2002:a05:6a02:294f:b0:c79:5ec2:4a68]) (user=ackerleytng job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:431e:b0:39f:54fb:e465 with SMTP id adf61e73a8af0-3aa5acd7603mr9313570637.50.1778186077180; Thu, 07 May 2026 13:34:37 -0700 (PDT) Date: Thu, 7 May 2026 13:34:24 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260507-gmem-inplace-conversion-v6-0-91ab5a8b19a4@google.com> X-Mailer: git-send-email 2.54.0.563.g4f69b47b94-goog Message-ID: Subject: [POC PATCH 3/5] KVM: selftests: Make guest_code_xsave more friendly From: Ackerley Tng To: devnull+ackerleytng.google.com@kernel.org Cc: ackerleytng@google.com, aik@amd.com, akpm@linux-foundation.org, andrew.jones@linux.dev, aneesh.kumar@kernel.org, axelrasmussen@google.com, baohua@kernel.org, bhe@redhat.com, binbin.wu@linux.intel.com, bp@alien8.de, brauner@kernel.org, chao.p.peng@linux.intel.com, chrisl@kernel.org, corbet@lwn.net, dave.hansen@linux.intel.com, david@kernel.org, forkloop@google.com, hpa@zytor.com, ira.weiny@intel.com, jgg@ziepe.ca, jmattson@google.com, jthoughton@google.com, kas@kernel.org, kasong@tencent.com, kvm@vger.kernel.org, liam@infradead.org, linux-coco@lists.linux.dev, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, michael.roth@amd.com, mingo@redhat.com, nphamcs@gmail.com, oupton@kernel.org, pankaj.gupta@amd.com, pbonzini@redhat.com, pratyush@kernel.org, qi.zheng@linux.dev, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, rostedt@goodmis.org, seanjc@google.com, shakeel.butt@linux.dev, shikemeng@huaweicloud.com, shivankg@amd.com, shuah@kernel.org, skhan@linuxfoundation.org, steven.price@arm.com, suzuki.poulose@arm.com, tabba@google.com, tglx@kernel.org, vannapurve@google.com, vbabka@kernel.org, weixugc@google.com, willy@infradead.org, wyihan@google.com, x86@kernel.org, yan.y.zhao@intel.com, youngjun.park@lge.com, yuanchu@google.com Content-Type: text/plain; charset="UTF-8" The original implementation of guest_code_xsave makes a jmp to guest_sev_es_code in inline assembly. When code that uses guest_sev_es_code is removed, guest_sev_es_code will be optimized out, leading to a linking error since guest_code_xsave still tries to jmp to guest_sev_es_code. Rewrite guest_code_xsave() to instead make a call, in C, to guest_sev_es_code(), so that usage of guest_sev_es_code() is made known to the compiler. This rewriting also gives a name to the xsave inline assembly, improving readability. Signed-off-by: Ackerley Tng --- .../selftests/kvm/x86/sev_smoke_test.c | 24 +++++++++++++------ 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/tools/testing/selftests/kvm/x86/sev_smoke_test.c b/tools/testing/selftests/kvm/x86/sev_smoke_test.c index 1a49ee3915864..8b859adf4cf6f 100644 --- a/tools/testing/selftests/kvm/x86/sev_smoke_test.c +++ b/tools/testing/selftests/kvm/x86/sev_smoke_test.c @@ -80,13 +80,23 @@ static void guest_sev_code(void) GUEST_DONE(); } -/* Stash state passed via VMSA before any compiled code runs. */ -extern void guest_code_xsave(void); -asm("guest_code_xsave:\n" - "mov $" __stringify(XFEATURE_MASK_X87_AVX) ", %eax\n" - "xor %edx, %edx\n" - "xsave (%rdi)\n" - "jmp guest_sev_es_code"); +static void xsave_all_registers(void *addr) +{ + __asm__ __volatile__( + "mov $" __stringify(XFEATURE_MASK_X87_AVX) ", %eax\n" + "xor %edx, %edx\n" + "xsave (%0)" + : + : "r"(addr) + : "eax", "edx", "memory" + ); +} + +static void guest_code_xsave(void *vmsa_gva) +{ + xsave_all_registers(vmsa_gva); + guest_sev_es_code(); +} static void compare_xsave(u8 *from_host, u8 *from_guest) { -- 2.54.0.563.g4f69b47b94-goog