KVM: Use alignment properties of vcpu to simplify FPU ops

Now we use a kmem cache for allocating vcpus, we can get the 16-byte
alignment required by fxsave & fxrstor instructions, and avoid
manually aligning the buffer.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index b362e8f8f832..7a34706f42be 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -45,10 +45,6 @@
 #define KVM_REFILL_PAGES 25
 #define KVM_MAX_CPUID_ENTRIES 40
 
-#define FX_IMAGE_SIZE 512
-#define FX_IMAGE_ALIGN 16
-#define FX_BUF_SIZE (2 * FX_IMAGE_SIZE + FX_IMAGE_ALIGN)
-
 #define DE_VECTOR 0
 #define NM_VECTOR 7
 #define DF_VECTOR 8
@@ -342,9 +338,8 @@ struct kvm_vcpu {
 
         struct kvm_guest_debug guest_debug;
 
-        char fx_buf[FX_BUF_SIZE];
-        char *host_fx_image;
-        char *guest_fx_image;
+        struct i387_fxsave_struct host_fx_image;
+        struct i387_fxsave_struct guest_fx_image;
         int fpu_active;
         int guest_fpu_loaded;
 
@@ -704,12 +699,12 @@ static inline unsigned long read_msr(unsigned long msr)
 }
 #endif
 
-static inline void fx_save(void *image)
+static inline void fx_save(struct i387_fxsave_struct *image)
 {
         asm ("fxsave (%0)":: "r" (image));
 }
 
-static inline void fx_restore(void *image)
+static inline void fx_restore(struct i387_fxsave_struct *image)
 {
         asm ("fxrstor (%0)":: "r" (image));
 }