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AJvYcCUI6k2KIg70bYDjUQmLgGieQd5PoHTkA8cD3ffe4wCUfpRfjSVf0Q686OZ99ltS9JFAuB4BeeBtJeRLyMw=@vger.kernel.org X-Gm-Message-State: AOJu0YyTRr/QQp//+oWwRz4791/13GfaNQTrM9chqIiXhdttv6zuyUWY jPtZtlt8XaqBpn8p1odFjv8xRfRD0o3eFluhaebdbR6Bu6IxRgsoL29clxjbEjkhLipO6P2xrKF hSb3n2H9eP+PJcO+fPri0su4SUA== X-Received: from pfblm12.prod.google.com ([2002:a05:6a00:3c8c:b0:829:7245:b797]) (user=ackerleytng job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a00:aa04:b0:824:a8f2:7de7 with SMTP id d2e1a72fcca58-82c960a6bcdmr260470b3a.60.1774568224072; Thu, 26 Mar 2026 16:37:04 -0700 (PDT) Date: Thu, 26 Mar 2026 16:36:41 -0700 In-Reply-To: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260326-gmem-inplace-conversion-v4-0-e202fe950ffd@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: Subject: [POC PATCH 3/6] KVM: selftests: Make guest_code_xsave more friendly From: Ackerley Tng To: ackerleytng@google.com Cc: 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, jroedel@suse.de, jthoughton@google.com, kasong@tencent.com, kvm@vger.kernel.org, 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, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, rostedt@goodmis.org, seanjc@google.com, 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, yuanchu@google.com Content-Transfer-Encoding: quoted-printable 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/testi= ng/selftests/kvm/x86/sev_smoke_test.c index 8bd37a476f159..7e69da01cecf4 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(); } =20 -/* 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(); +} =20 static void compare_xsave(u8 *from_host, u8 *from_guest) { --=20 2.53.0.1018.g2bb0e51243-goog