From: Laurent Vivier <[EMAIL PROTECTED]>

This patch lets GCC to determine which registers to save when we
switch to/from a VCPU in the case of AMD i386

* Original code saves following registers:

    ebx, ecx, edx, esi, edi, ebp

* Patched code:

  - informs GCC that we modify following registers
    using the clobber description:

    ebx, ecx, edx, esi, edi

  - rbp is saved (pop/push) because GCC seems to ignore its use in the clobber
    description.

Signed-off-by: Laurent Vivier <[EMAIL PROTECTED]>
Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>
---
 drivers/kvm/svm.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 1298bde..cdd4fd2 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1501,8 +1501,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct 
kvm_run *kvm_run)
 #ifdef CONFIG_X86_64
                "push %%rbp; \n\t"
 #else
-               "push %%ebx; push %%ecx; push %%edx;"
-               "push %%esi; push %%edi; push %%ebp;"
+               "push %%ebp; \n\t"
 #endif
 
 #ifdef CONFIG_X86_64
@@ -1573,8 +1572,7 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct 
kvm_run *kvm_run)
                "mov %%edi, %c[rdi](%[svm]) \n\t"
                "mov %%ebp, %c[rbp](%[svm]) \n\t"
 
-               "pop  %%ebp; pop  %%edi; pop  %%esi;"
-               "pop  %%edx; pop  %%ecx; pop  %%ebx; \n\t"
+               "pop  %%ebp; \n\t"
 #endif
                :
                : [svm]"a"(svm),
@@ -1599,6 +1597,8 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct 
kvm_run *kvm_run)
 #ifdef CONFIG_X86_64
                , "rbx", "rcx", "rdx", "rsi", "rdi"
                , "r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15"
+#else
+               , "ebx", "ecx", "edx" , "esi", "edi"
 #endif
                );
 
-- 
1.5.3.7


-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2005.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
kvm-devel mailing list
kvm-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/kvm-devel

Reply via email to