diff mbox series

[2/8] KVM: SVM: replace regs argument of __svm_vcpu_run with vcpu_svm

Message ID 20221107145436.276079-3-pbonzini@redhat.com
State New
Headers
Series KVM: SVM: fixes for vmentry code |

Commit Message

Paolo Bonzini Nov. 7, 2022, 2:54 p.m. UTC 
  Since registers are reachable through vcpu_svm, and we will
need to access more fields of that struct, pass it instead
of the regs[] array.

No functional change intended.

Cc: stable@vger.kernel.org
Fixes: f14eec0a3203 ("KVM: SVM: move more vmentry code to assembly")
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kernel/asm-offsets.c |  6 ++++++
 arch/x86/kvm/svm/svm.c        |  2 +-
 arch/x86/kvm/svm/svm.h        |  2 +-
 arch/x86/kvm/svm/vmenter.S    | 36 +++++++++++++++++------------------
 4 files changed, 26 insertions(+), 20 deletions(-)

Comments

Sean Christopherson Nov. 7, 2022, 5:10 p.m. UTC | #1 
On Mon, Nov 07, 2022, Paolo Bonzini wrote:
> diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
> index 723f8534986c..8fac744361e5 100644
> --- a/arch/x86/kvm/svm/vmenter.S
> +++ b/arch/x86/kvm/svm/vmenter.S

Needs to include asm/asm-offsets.h, otherwise the compiler may think that
SVM_vcpu_arch_regs is a symbol.

  ERROR: modpost: "SVM_vcpu_arch_regs" [arch/x86/kvm/kvm-amd.ko] undefined!

diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 8fac744361e5..8d0b0781462e 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/linkage.h>
 #include <asm/asm.h>
+#include <asm/asm-offsets.h>
 #include <asm/bitsperlong.h>
 #include <asm/kvm_vcpu_regs.h>
 #include <asm/nospec-branch.h>

> @@ -8,23 +8,23 @@
>  #define WORD_SIZE (BITS_PER_LONG / 8)
>  
>  /* Intentionally omit RAX as it's context switched by hardware */
> -#define VCPU_RCX	__VCPU_REGS_RCX * WORD_SIZE
> -#define VCPU_RDX	__VCPU_REGS_RDX * WORD_SIZE
> -#define VCPU_RBX	__VCPU_REGS_RBX * WORD_SIZE
> +#define VCPU_RCX	(SVM_vcpu_arch_regs + __VCPU_REGS_RCX * WORD_SIZE)
> +#define VCPU_RDX	(SVM_vcpu_arch_regs + __VCPU_REGS_RDX * WORD_SIZE)
> +#define VCPU_RBX	(SVM_vcpu_arch_regs + __VCPU_REGS_RBX * WORD_SIZE)
>  /* Intentionally omit RSP as it's context switched by hardware */
> -#define VCPU_RBP	__VCPU_REGS_RBP * WORD_SIZE
> -#define VCPU_RSI	__VCPU_REGS_RSI * WORD_SIZE
> -#define VCPU_RDI	__VCPU_REGS_RDI * WORD_SIZE
> +#define VCPU_RBP	(SVM_vcpu_arch_regs + __VCPU_REGS_RBP * WORD_SIZE)
> +#define VCPU_RSI	(SVM_vcpu_arch_regs + __VCPU_REGS_RSI * WORD_SIZE)
> +#define VCPU_RDI	(SVM_vcpu_arch_regs + __VCPU_REGS_RDI * WORD_SIZE)
>  
>  #ifdef CONFIG_X86_64
> -#define VCPU_R8		__VCPU_REGS_R8  * WORD_SIZE
> -#define VCPU_R9		__VCPU_REGS_R9  * WORD_SIZE
> -#define VCPU_R10	__VCPU_REGS_R10 * WORD_SIZE
> -#define VCPU_R11	__VCPU_REGS_R11 * WORD_SIZE
> -#define VCPU_R12	__VCPU_REGS_R12 * WORD_SIZE
> -#define VCPU_R13	__VCPU_REGS_R13 * WORD_SIZE
> -#define VCPU_R14	__VCPU_REGS_R14 * WORD_SIZE
> -#define VCPU_R15	__VCPU_REGS_R15 * WORD_SIZE
> +#define VCPU_R8		(SVM_vcpu_arch_regs + __VCPU_REGS_R8  * WORD_SIZE)
> +#define VCPU_R9		(SVM_vcpu_arch_regs + __VCPU_REGS_R9  * WORD_SIZE)
> +#define VCPU_R10	(SVM_vcpu_arch_regs + __VCPU_REGS_R10 * WORD_SIZE)
> +#define VCPU_R11	(SVM_vcpu_arch_regs + __VCPU_REGS_R11 * WORD_SIZE)
> +#define VCPU_R12	(SVM_vcpu_arch_regs + __VCPU_REGS_R12 * WORD_SIZE)
> +#define VCPU_R13	(SVM_vcpu_arch_regs + __VCPU_REGS_R13 * WORD_SIZE)
> +#define VCPU_R14	(SVM_vcpu_arch_regs + __VCPU_REGS_R14 * WORD_SIZE)
> +#define VCPU_R15	(SVM_vcpu_arch_regs + __VCPU_REGS_R15 * WORD_SIZE)
>  #endif
Paolo Bonzini Nov. 7, 2022, 5:22 p.m. UTC | #2 
On 11/7/22 18:10, Sean Christopherson wrote:
> Needs to include asm/asm-offsets.h, otherwise the compiler may think that
> SVM_vcpu_arch_regs is a symbol.
> 
>    ERROR: modpost: "SVM_vcpu_arch_regs" [arch/x86/kvm/kvm-amd.ko] undefined!
> 
> diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
> index 8fac744361e5..8d0b0781462e 100644
> --- a/arch/x86/kvm/svm/vmenter.S
> +++ b/arch/x86/kvm/svm/vmenter.S
> @@ -1,6 +1,7 @@
>   /* SPDX-License-Identifier: GPL-2.0 */
>   #include <linux/linkage.h>
>   #include <asm/asm.h>
> +#include <asm/asm-offsets.h>
>   #include <asm/bitsperlong.h>
>   #include <asm/kvm_vcpu_regs.h>
>   #include <asm/nospec-branch.h>

Yeah, it's included slightly later (I did test each patch independently, 
but I'm not sure how it ended up disappearing from this one).

Paolo
diff mbox series

Patch

diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index cb50589a7102..85de7e4fe59a 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -20,6 +20,7 @@ 
 #include <asm/tlbflush.h>
 #include <asm/tdx.h>
 #include "../kvm/vmx/vmx.h"
+#include "../kvm/svm/svm.h"
 
 #ifdef CONFIG_XEN
 #include <xen/interface/xen.h>
@@ -109,6 +110,11 @@  static void __used common(void)
 	OFFSET(TSS_sp1, tss_struct, x86_tss.sp1);
 	OFFSET(TSS_sp2, tss_struct, x86_tss.sp2);
 
+	if (IS_ENABLED(CONFIG_KVM_AMD)) {
+		BLANK();
+		OFFSET(SVM_vcpu_arch_regs, vcpu_svm, vcpu.arch.regs);
+	}
+
 	if (IS_ENABLED(CONFIG_KVM_INTEL)) {
 		BLANK();
 		OFFSET(VMX_spec_ctrl, vcpu_vmx, spec_ctrl);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index cd71f53590b2..4cfa62e66a0e 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3931,7 +3931,7 @@  static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu)
 		 * vmcb02 when switching vmcbs for nested virtualization.
 		 */
 		vmload(svm->vmcb01.pa);
-		__svm_vcpu_run(vmcb_pa, (unsigned long *)&vcpu->arch.regs);
+		__svm_vcpu_run(vmcb_pa, svm);
 		vmsave(svm->vmcb01.pa);
 
 		vmload(__sme_page_pa(sd->save_area));
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 222856788153..5f8dfc9cd9a7 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -484,6 +484,6 @@  void sev_es_unmap_ghcb(struct vcpu_svm *svm);
 /* vmenter.S */
 
 void __svm_sev_es_vcpu_run(unsigned long vmcb_pa);
-void __svm_vcpu_run(unsigned long vmcb_pa, unsigned long *regs);
+void __svm_vcpu_run(unsigned long vmcb_pa, struct vcpu_svm *svm);
 
 #endif
diff --git a/arch/x86/kvm/svm/vmenter.S b/arch/x86/kvm/svm/vmenter.S
index 723f8534986c..8fac744361e5 100644
--- a/arch/x86/kvm/svm/vmenter.S
+++ b/arch/x86/kvm/svm/vmenter.S
@@ -8,23 +8,23 @@ 
 #define WORD_SIZE (BITS_PER_LONG / 8)
 
 /* Intentionally omit RAX as it's context switched by hardware */
-#define VCPU_RCX	__VCPU_REGS_RCX * WORD_SIZE
-#define VCPU_RDX	__VCPU_REGS_RDX * WORD_SIZE
-#define VCPU_RBX	__VCPU_REGS_RBX * WORD_SIZE
+#define VCPU_RCX	(SVM_vcpu_arch_regs + __VCPU_REGS_RCX * WORD_SIZE)
+#define VCPU_RDX	(SVM_vcpu_arch_regs + __VCPU_REGS_RDX * WORD_SIZE)
+#define VCPU_RBX	(SVM_vcpu_arch_regs + __VCPU_REGS_RBX * WORD_SIZE)
 /* Intentionally omit RSP as it's context switched by hardware */
-#define VCPU_RBP	__VCPU_REGS_RBP * WORD_SIZE
-#define VCPU_RSI	__VCPU_REGS_RSI * WORD_SIZE
-#define VCPU_RDI	__VCPU_REGS_RDI * WORD_SIZE
+#define VCPU_RBP	(SVM_vcpu_arch_regs + __VCPU_REGS_RBP * WORD_SIZE)
+#define VCPU_RSI	(SVM_vcpu_arch_regs + __VCPU_REGS_RSI * WORD_SIZE)
+#define VCPU_RDI	(SVM_vcpu_arch_regs + __VCPU_REGS_RDI * WORD_SIZE)
 
 #ifdef CONFIG_X86_64
-#define VCPU_R8		__VCPU_REGS_R8  * WORD_SIZE
-#define VCPU_R9		__VCPU_REGS_R9  * WORD_SIZE
-#define VCPU_R10	__VCPU_REGS_R10 * WORD_SIZE
-#define VCPU_R11	__VCPU_REGS_R11 * WORD_SIZE
-#define VCPU_R12	__VCPU_REGS_R12 * WORD_SIZE
-#define VCPU_R13	__VCPU_REGS_R13 * WORD_SIZE
-#define VCPU_R14	__VCPU_REGS_R14 * WORD_SIZE
-#define VCPU_R15	__VCPU_REGS_R15 * WORD_SIZE
+#define VCPU_R8		(SVM_vcpu_arch_regs + __VCPU_REGS_R8  * WORD_SIZE)
+#define VCPU_R9		(SVM_vcpu_arch_regs + __VCPU_REGS_R9  * WORD_SIZE)
+#define VCPU_R10	(SVM_vcpu_arch_regs + __VCPU_REGS_R10 * WORD_SIZE)
+#define VCPU_R11	(SVM_vcpu_arch_regs + __VCPU_REGS_R11 * WORD_SIZE)
+#define VCPU_R12	(SVM_vcpu_arch_regs + __VCPU_REGS_R12 * WORD_SIZE)
+#define VCPU_R13	(SVM_vcpu_arch_regs + __VCPU_REGS_R13 * WORD_SIZE)
+#define VCPU_R14	(SVM_vcpu_arch_regs + __VCPU_REGS_R14 * WORD_SIZE)
+#define VCPU_R15	(SVM_vcpu_arch_regs + __VCPU_REGS_R15 * WORD_SIZE)
 #endif
 
 .section .noinstr.text, "ax"
@@ -32,7 +32,7 @@ 
 /**
  * __svm_vcpu_run - Run a vCPU via a transition to SVM guest mode
  * @vmcb_pa:	unsigned long
- * @regs:	unsigned long * (to guest registers)
+ * @svm:	struct vcpu_svm *
  */
 SYM_FUNC_START(__svm_vcpu_run)
 	push %_ASM_BP
@@ -47,13 +47,13 @@  SYM_FUNC_START(__svm_vcpu_run)
 #endif
 	push %_ASM_BX
 
-	/* Save @regs. */
+	/* Save @svm. */
 	push %_ASM_ARG2
 
 	/* Save @vmcb. */
 	push %_ASM_ARG1
 
-	/* Move @regs to RAX. */
+	/* Move @svm to RAX. */
 	mov %_ASM_ARG2, %_ASM_AX
 
 	/* Load guest registers. */
@@ -89,7 +89,7 @@  SYM_FUNC_START(__svm_vcpu_run)
 	FILL_RETURN_BUFFER %_ASM_AX, RSB_CLEAR_LOOPS, X86_FEATURE_RETPOLINE
 #endif
 
-	/* "POP" @regs to RAX. */
+	/* "POP" @svm to RAX. */
 	pop %_ASM_AX
 
 	/* Save all guest registers.  */