[PATCH 4/7] KVM: SVM: replace argument of __svm_vcpu_run with vcpu_svm

From: Paolo Bonzini
Date: Fri Oct 28 2022 - 19:09:39 EST


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.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
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(-)

diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 90da275ad223..7f1dd1138117 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_vcpu_arch_regs, vcpu_vmx, vcpu.arch.regs);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b793cfdce68d..64f5f0544b4f 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3932,7 +3932,7 @@ 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. */
--
2.31.1