From: Yosry Ahmed <yosry@kernel.org>
To: Sean Christopherson <seanjc@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
Yosry Ahmed <yosry@kernel.org>
Subject: [PATCH v3 05/10] KVM: selftests: Reuse GPR switching logic for nVMX
Date: Mon, 29 Jun 2026 18:37:40 +0000 [thread overview]
Message-ID: <20260629183746.699840-6-yosry@kernel.org> (raw)
In-Reply-To: <20260629183746.699840-1-yosry@kernel.org>
Reuse the GPR switching logic for nVMX by defining VMX_SWITCH_GPRS_ASM,
which is essentially the same as SVM_SWITCH_GPRS_ASM but also switches
RAX, replacing the push/pop of a subset of the registers.
The long clobber list of registers is no longer needed as registers are
saved and restored appropriately (and not clobbered by L2).
Define VMX_SWITCH_GPRS_ASM before including evmcs.h, such that it can be
used by evmcs_vmlaunch() and evmcs_vmresume().
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
---
.../testing/selftests/kvm/include/x86/evmcs.h | 40 ++++--------
tools/testing/selftests/kvm/include/x86/vmx.h | 63 +++++++++----------
2 files changed, 41 insertions(+), 62 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/x86/evmcs.h b/tools/testing/selftests/kvm/include/x86/evmcs.h
index be79bda024bf1..98268be1aa5b2 100644
--- a/tools/testing/selftests/kvm/include/x86/evmcs.h
+++ b/tools/testing/selftests/kvm/include/x86/evmcs.h
@@ -1207,30 +1207,22 @@ static inline int evmcs_vmlaunch(void)
current_evmcs->hv_clean_fields = 0;
- __asm__ __volatile__("push %%rbp;"
- "push %%rcx;"
- "push %%rdx;"
- "push %%rsi;"
- "push %%rdi;"
- "push $0;"
+ __asm__ __volatile__("push $0;"
"mov %%rsp, (%[host_rsp]);"
"lea 1f(%%rip), %%rax;"
"mov %%rax, (%[host_rip]);"
+ VMX_SWITCH_GPRS_ASM
"vmlaunch;"
"incq (%%rsp);"
- "1: pop %%rax;"
- "pop %%rdi;"
- "pop %%rsi;"
- "pop %%rdx;"
- "pop %%rcx;"
- "pop %%rbp;"
+ "1: ;"
+ VMX_SWITCH_GPRS_ASM
+ "pop %%rax;"
: [ret]"=&a"(ret)
: [host_rsp]"r"
((u64)¤t_evmcs->host_rsp),
[host_rip]"r"
((u64)¤t_evmcs->host_rip)
- : "memory", "cc", "rbx", "r8", "r9", "r10",
- "r11", "r12", "r13", "r14", "r15");
+ : "memory", "cc");
return ret;
}
@@ -1246,30 +1238,22 @@ static inline int evmcs_vmresume(void)
/* HOST_RSP */
current_evmcs->hv_clean_fields &= ~HV_VMX_ENLIGHTENED_CLEAN_FIELD_HOST_POINTER;
- __asm__ __volatile__("push %%rbp;"
- "push %%rcx;"
- "push %%rdx;"
- "push %%rsi;"
- "push %%rdi;"
- "push $0;"
+ __asm__ __volatile__("push $0;"
"mov %%rsp, (%[host_rsp]);"
"lea 1f(%%rip), %%rax;"
"mov %%rax, (%[host_rip]);"
+ VMX_SWITCH_GPRS_ASM
"vmresume;"
"incq (%%rsp);"
- "1: pop %%rax;"
- "pop %%rdi;"
- "pop %%rsi;"
- "pop %%rdx;"
- "pop %%rcx;"
- "pop %%rbp;"
+ "1: ;"
+ VMX_SWITCH_GPRS_ASM
+ "pop %%rax;"
: [ret]"=&a"(ret)
: [host_rsp]"r"
((u64)¤t_evmcs->host_rsp),
[host_rip]"r"
((u64)¤t_evmcs->host_rip)
- : "memory", "cc", "rbx", "r8", "r9", "r10",
- "r11", "r12", "r13", "r14", "r15");
+ : "memory", "cc");
return ret;
}
diff --git a/tools/testing/selftests/kvm/include/x86/vmx.h b/tools/testing/selftests/kvm/include/x86/vmx.h
index 4bcfd60e3aecb..a808dc21c9f21 100644
--- a/tools/testing/selftests/kvm/include/x86/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86/vmx.h
@@ -290,6 +290,23 @@ struct vmx_msr_entry {
u64 value;
} __attribute__ ((aligned(16)));
+#define VMX_SWITCH_GPRS_ASM \
+ GUEST_SWITCH_GPR_ASM(rax, GUEST_REGS_RAX) \
+ GUEST_SWITCH_GPR_ASM(rbx, GUEST_REGS_RBX) \
+ GUEST_SWITCH_GPR_ASM(rcx, GUEST_REGS_RCX) \
+ GUEST_SWITCH_GPR_ASM(rdx, GUEST_REGS_RDX) \
+ GUEST_SWITCH_GPR_ASM(rbp, GUEST_REGS_RBP) \
+ GUEST_SWITCH_GPR_ASM(rsi, GUEST_REGS_RSI) \
+ GUEST_SWITCH_GPR_ASM(rdi, GUEST_REGS_RDI) \
+ GUEST_SWITCH_GPR_ASM(r8, GUEST_REGS_R8) \
+ GUEST_SWITCH_GPR_ASM(r9, GUEST_REGS_R9) \
+ GUEST_SWITCH_GPR_ASM(r10, GUEST_REGS_R10) \
+ GUEST_SWITCH_GPR_ASM(r11, GUEST_REGS_R11) \
+ GUEST_SWITCH_GPR_ASM(r12, GUEST_REGS_R12) \
+ GUEST_SWITCH_GPR_ASM(r13, GUEST_REGS_R13) \
+ GUEST_SWITCH_GPR_ASM(r14, GUEST_REGS_R14) \
+ GUEST_SWITCH_GPR_ASM(r15, GUEST_REGS_R15)
+
#include "evmcs.h"
static inline int vmxon(u64 phys)
@@ -363,9 +380,6 @@ static inline u64 vmptrstz(void)
return value;
}
-/*
- * No guest state (e.g. GPRs) is established by this vmlaunch.
- */
static inline int vmlaunch(void)
{
int ret;
@@ -373,34 +387,23 @@ static inline int vmlaunch(void)
if (enable_evmcs)
return evmcs_vmlaunch();
- __asm__ __volatile__("push %%rbp;"
- "push %%rcx;"
- "push %%rdx;"
- "push %%rsi;"
- "push %%rdi;"
- "push $0;"
+ __asm__ __volatile__("push $0;"
"vmwrite %%rsp, %[host_rsp];"
"lea 1f(%%rip), %%rax;"
"vmwrite %%rax, %[host_rip];"
+ VMX_SWITCH_GPRS_ASM
"vmlaunch;"
"incq (%%rsp);"
- "1: pop %%rax;"
- "pop %%rdi;"
- "pop %%rsi;"
- "pop %%rdx;"
- "pop %%rcx;"
- "pop %%rbp;"
+ "1: ;"
+ VMX_SWITCH_GPRS_ASM
+ "pop %%rax;"
: [ret]"=&a"(ret)
: [host_rsp]"r"((u64)HOST_RSP),
[host_rip]"r"((u64)HOST_RIP)
- : "memory", "cc", "rbx", "r8", "r9", "r10",
- "r11", "r12", "r13", "r14", "r15");
+ : "memory", "cc");
return ret;
}
-/*
- * No guest state (e.g. GPRs) is established by this vmresume.
- */
static inline int vmresume(void)
{
int ret;
@@ -408,28 +411,20 @@ static inline int vmresume(void)
if (enable_evmcs)
return evmcs_vmresume();
- __asm__ __volatile__("push %%rbp;"
- "push %%rcx;"
- "push %%rdx;"
- "push %%rsi;"
- "push %%rdi;"
- "push $0;"
+ __asm__ __volatile__("push $0;"
"vmwrite %%rsp, %[host_rsp];"
"lea 1f(%%rip), %%rax;"
"vmwrite %%rax, %[host_rip];"
+ VMX_SWITCH_GPRS_ASM
"vmresume;"
"incq (%%rsp);"
- "1: pop %%rax;"
- "pop %%rdi;"
- "pop %%rsi;"
- "pop %%rdx;"
- "pop %%rcx;"
- "pop %%rbp;"
+ "1: ;"
+ VMX_SWITCH_GPRS_ASM
+ "pop %%rax;"
: [ret]"=&a"(ret)
: [host_rsp]"r"((u64)HOST_RSP),
[host_rip]"r"((u64)HOST_RIP)
- : "memory", "cc", "rbx", "r8", "r9", "r10",
- "r11", "r12", "r13", "r14", "r15");
+ : "memory", "cc");
return ret;
}
--
2.55.0.rc0.799.gd6f94ed593-goog
next prev parent reply other threads:[~2026-06-29 18:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 18:37 [PATCH v3 00/10] KVM: selftests: Stress save+restore and #PF (ft. nested) Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 01/10] KVM: selftests: Move STR() and XSTR() definitions to test_util.h Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 02/10] KVM: selftests: Fix RAX and RFLAGS VMCB offsets when running L2 Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 03/10] KVM: selftests: Use an array for guest_regs (and fix offsets) Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 04/10] KVM: selftests: Move GPR load/save definitions outside of nSVM code Yosry Ahmed
2026-06-29 18:37 ` Yosry Ahmed [this message]
2026-06-29 18:49 ` [PATCH v3 05/10] KVM: selftests: Reuse GPR switching logic for nVMX sashiko-bot
2026-06-29 20:26 ` Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 06/10] KVM: selftests: Drop HORRIFIC_L2_UCALL_CLOBBER_HACK Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 07/10] KVM: selftests: Add basic stress test for save+restore and #PF handling Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 08/10] KVM: selftests: Trigger save+restore randomly in the #PF stress test Yosry Ahmed
2026-06-29 18:48 ` sashiko-bot
2026-06-29 20:29 ` Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 09/10] KVM: selftests: Support running stress save+restore and #PF test in L2 Yosry Ahmed
2026-06-29 18:37 ` [PATCH v3 10/10] KVM: selftests: Trigger L2->L1 exits stress save+restore and #PF test Yosry Ahmed
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