diff options
| author | Laurent Vivier <Laurent.Vivier@bull.net> | 2007-10-25 14:18:53 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2008-01-30 17:52:56 +0200 |
| commit | 54a08c0449683f763dc69e653d17e8c120e16299 (patch) | |
| tree | 959fd4654d64837d2eeb87d37fe1506a295f5cb7 /drivers/kvm/svm.c | |
| parent | ff593e5abebd899b0b41c11280e2fbeff4103375 (diff) | |
KVM: SVM: Let gcc to choose which registers to save (x86_64)
This patch lets GCC to determine which registers to save when we
switch to/from a VCPU in the case of AMD x86_64.
* Original code saves following registers:
rbx, rcx, rdx, rsi, rdi, rbp,
r8, r9, r10, r11, r12, r13, r14, r15
* Patched code:
- informs GCC that we modify following registers
using the clobber description:
rbx, rcx, rdx, rsi, rdi
r8, r9, r10, r11, r12, r13, r14, r15
- rbp is saved (pop/push) because GCC seems to ignore its use in the clobber
description.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'drivers/kvm/svm.c')
| -rw-r--r-- | drivers/kvm/svm.c | 17 |
1 files changed, 8 insertions, 9 deletions
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index beb1e684b68..debd0912a01 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -1499,10 +1499,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) asm volatile ( #ifdef CONFIG_X86_64 - "push %%rbx; push %%rcx; push %%rdx;" - "push %%rsi; push %%rdi; push %%rbp;" - "push %%r8; push %%r9; push %%r10; push %%r11;" - "push %%r12; push %%r13; push %%r14; push %%r15;" + "push %%rbp; \n\t" #else "push %%ebx; push %%ecx; push %%edx;" "push %%esi; push %%edi; push %%ebp;" @@ -1567,10 +1564,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) "mov %%r14, %c[r14](%[svm]) \n\t" "mov %%r15, %c[r15](%[svm]) \n\t" - "pop %%r15; pop %%r14; pop %%r13; pop %%r12;" - "pop %%r11; pop %%r10; pop %%r9; pop %%r8;" - "pop %%rbp; pop %%rdi; pop %%rsi;" - "pop %%rdx; pop %%rcx; pop %%rbx; \n\t" + "pop %%rbp; \n\t" #else "mov %%ebx, %c[rbx](%[svm]) \n\t" "mov %%ecx, %c[rcx](%[svm]) \n\t" @@ -1601,7 +1595,12 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) [r14]"i"(offsetof(struct vcpu_svm, vcpu.regs[VCPU_REGS_R14])), [r15]"i"(offsetof(struct vcpu_svm, vcpu.regs[VCPU_REGS_R15])) #endif - : "cc", "memory"); + : "cc", "memory" +#ifdef CONFIG_X86_64 + , "rbx", "rcx", "rdx", "rsi", "rdi" + , "r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15" +#endif + ); if ((svm->vmcb->save.dr7 & 0xff)) load_db_regs(svm->host_db_regs); |