diff options
| author | Yosry Ahmed <yosry@kernel.org> | 2026-07-28 17:42:25 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2026-07-29 05:45:26 -0700 |
| commit | 2bdef77c6019c3439e7a07a82ed76dde2747633f (patch) | |
| tree | 12b597d9bd2564ab92b28dce2f2877bac1cd748f /tools/testing/selftests/kvm/lib | |
| parent | 3d31fea7b6d1a11ab6e7bea61c0442d1ec2fea5a (diff) | |
KVM: selftests: Drop HORRIFIC_L2_UCALL_CLOBBER_HACK
Now that nVMX test codes preserves GPRs across nested VM-Exits
(specifically RBP, RDX, and RDI among others), drop the ucall-specific
hack to avoid clobbering these registers.
Assisted-by: Gemini:gemini-3.1-pro
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260728174232.2423257-7-yosry@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'tools/testing/selftests/kvm/lib')
| -rw-r--r-- | tools/testing/selftests/kvm/lib/x86/ucall.c | 32 |
1 files changed, 2 insertions, 30 deletions
diff --git a/tools/testing/selftests/kvm/lib/x86/ucall.c b/tools/testing/selftests/kvm/lib/x86/ucall.c index e7dd5791959b..38050c60a067 100644 --- a/tools/testing/selftests/kvm/lib/x86/ucall.c +++ b/tools/testing/selftests/kvm/lib/x86/ucall.c @@ -10,36 +10,8 @@ void ucall_arch_do_ucall(gva_t uc) { - /* - * FIXME: Revert this hack (the entire commit that added it) once nVMX - * preserves L2 GPRs across a nested VM-Exit. If a ucall from L2, e.g. - * to do a GUEST_SYNC(), lands the vCPU in L1, any and all GPRs can be - * clobbered by L1. Save and restore non-volatile GPRs (clobbering RBP - * in particular is problematic) along with RDX and RDI (which are - * inputs), and clobber volatile GPRs. *sigh* - */ -#define HORRIFIC_L2_UCALL_CLOBBER_HACK \ - "rcx", "rsi", "r8", "r9", "r10", "r11" - - asm volatile("push %%rbp\n\t" - "push %%r15\n\t" - "push %%r14\n\t" - "push %%r13\n\t" - "push %%r12\n\t" - "push %%rbx\n\t" - "push %%rdx\n\t" - "push %%rdi\n\t" - "in %[port], %%al\n\t" - "pop %%rdi\n\t" - "pop %%rdx\n\t" - "pop %%rbx\n\t" - "pop %%r12\n\t" - "pop %%r13\n\t" - "pop %%r14\n\t" - "pop %%r15\n\t" - "pop %%rbp\n\t" - : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory", - HORRIFIC_L2_UCALL_CLOBBER_HACK); + asm volatile("in %[port], %%al" + : : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory"); } void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu) |