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Bae" , Sean Christopherson Subject: [PATCH 3/8] KVM: SVM: prepare for making SPEC_CTRL switch common with VMX Date: Tue, 28 Apr 2026 07:05:02 -0400 Message-ID: <20260428110507.11248-4-pbonzini@redhat.com> In-Reply-To: <20260428110507.11248-1-pbonzini@redhat.com> References: <20260428110507.11248-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Remove the local labels and restrict RESTORE_*_BODY to just the restore code itself. Since the alternatives are different between VMX and SVM, having labels in the per-vendor file and jumps in another would be too confusing. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/svm/vmenter.S | 54 +++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 24 deletions(-) diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S index d47c5c93c991..aa655b519fe0 100644 --- a/arch/x86/kvm/svm/vmenter.S +++ b/arch/x86/kvm/svm/vmenter.S @@ -39,10 +39,8 @@ ALTERNATIVE_2 "", \ "jmp 800f", X86_FEATURE_MSR_SPEC_CTRL, \ "", X86_FEATURE_V_SPEC_CTRL -801: .endm -.macro RESTORE_GUEST_SPEC_CTRL_BODY -800: +.macro RESTORE_GUEST_SPEC_CTRL_BODY guest_spec_ctrl:req, label:req /* * SPEC_CTRL handling: if the guest's SPEC_CTRL value differs from the * host's, write the MSR. This is kept out-of-line so that the common @@ -53,24 +51,23 @@ * and vmentry. */ #ifdef CONFIG_X86_64 - mov SVM_spec_ctrl(%rdi), %rdx + mov \guest_spec_ctrl, %rdx cmp PER_CPU_VAR(x86_spec_ctrl_current), %rdx - je 801b + je \label movl %edx, %eax shr $32, %rdx #else - mov SVM_spec_ctrl(%edi), %eax + mov \guest_spec_ctrl, %eax mov PER_CPU_VAR(x86_spec_ctrl_current), %ecx xor %eax, %ecx - mov SVM_spec_ctrl + 4(%edi), %edx + mov 4 + \guest_spec_ctrl, %edx mov PER_CPU_VAR(x86_spec_ctrl_current + 4), %esi xor %edx, %esi or %esi, %ecx - je 801b + je \label #endif mov $MSR_IA32_SPEC_CTRL, %ecx wrmsr - jmp 801b .endm .macro RESTORE_HOST_SPEC_CTRL @@ -78,10 +75,8 @@ ALTERNATIVE_2 "", \ "jmp 900f", X86_FEATURE_MSR_SPEC_CTRL, \ "", X86_FEATURE_V_SPEC_CTRL -901: .endm -.macro RESTORE_HOST_SPEC_CTRL_BODY spec_ctrl_intercepted:req -900: +.macro RESTORE_HOST_SPEC_CTRL_BODY guest_spec_ctrl:req, spec_ctrl_intercepted:req, label:req /* Same for after vmexit. */ mov $MSR_IA32_SPEC_CTRL, %ecx @@ -92,28 +87,27 @@ cmpb $0, \spec_ctrl_intercepted jnz 998f rdmsr - movl %eax, SVM_spec_ctrl(%_ASM_DI) - movl %edx, SVM_spec_ctrl + 4(%_ASM_DI) + movl %eax, \guest_spec_ctrl + movl %edx, 4 + \guest_spec_ctrl 998: /* Now restore the host value of the MSR if different from the guest's. */ #ifdef CONFIG_X86_64 mov PER_CPU_VAR(x86_spec_ctrl_current), %rdx - cmp SVM_spec_ctrl(%rdi), %rdx - je 901b + cmp \guest_spec_ctrl, %rdx + je \label movl %edx, %eax shr $32, %rdx #else mov PER_CPU_VAR(x86_spec_ctrl_current), %eax - mov SVM_spec_ctrl(%edi), %esi + mov \guest_spec_ctrl, %esi xor %eax, %esi mov PER_CPU_VAR(x86_spec_ctrl_current + 4), %edx - mov SVM_spec_ctrl + 4(%edi), %edi + mov 4 + \guest_spec_ctrl, %edi xor %edx, %edi or %edi, %esi - je 901b + je \label #endif wrmsr - jmp 901b .endm #define SVM_CLEAR_CPU_BUFFERS \ @@ -162,6 +156,7 @@ SYM_FUNC_START(__svm_vcpu_run) /* Clobbers RAX, RCX, RDX (and ESI on 32-bit), consumes RDI (@svm). */ RESTORE_GUEST_SPEC_CTRL +801: /* * Use a single vmcb (vmcb01 because it's always valid) for @@ -242,6 +237,7 @@ SYM_FUNC_START(__svm_vcpu_run) * and RSP (pointer to @spec_ctrl_intercepted). */ RESTORE_HOST_SPEC_CTRL +901: /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be @@ -295,8 +291,12 @@ SYM_FUNC_START(__svm_vcpu_run) pop %_ASM_BP RET - RESTORE_GUEST_SPEC_CTRL_BODY - RESTORE_HOST_SPEC_CTRL_BODY (%_ASM_SP) +800: + RESTORE_GUEST_SPEC_CTRL_BODY SVM_spec_ctrl(%_ASM_DI), 801b + jmp 801b +900: + RESTORE_HOST_SPEC_CTRL_BODY SVM_spec_ctrl(%_ASM_DI), (%_ASM_SP), 901b + jmp 901b 10: cmpb $0, _ASM_RIP(virt_rebooting) jne 2b @@ -362,6 +362,7 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) /* Clobbers RAX, RCX, and RDX (@hostsa), consumes RDI (@svm). */ RESTORE_GUEST_SPEC_CTRL +801: /* Get svm->current_vmcb->pa into RAX. */ mov SVM_current_vmcb(%rdi), %rax @@ -378,6 +379,7 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) /* Clobbers RAX, RCX, RDX, consumes RDI (@svm) and RSI (@spec_ctrl_intercepted). */ RESTORE_HOST_SPEC_CTRL +901: /* * Mitigate RETBleed for AMD/Hygon Zen uarch. RET should be @@ -391,8 +393,12 @@ SYM_FUNC_START(__svm_sev_es_vcpu_run) FRAME_END RET - RESTORE_GUEST_SPEC_CTRL_BODY - RESTORE_HOST_SPEC_CTRL_BODY %sil +800: + RESTORE_GUEST_SPEC_CTRL_BODY SVM_spec_ctrl(%_ASM_DI), 801b + jmp 801b +900: + RESTORE_HOST_SPEC_CTRL_BODY SVM_spec_ctrl(%_ASM_DI), %sil, 901b + jmp 901b 3: cmpb $0, virt_rebooting(%rip) jne 2b -- 2.52.0