KVM: 16-byte mmio support

Since sse instructions can issue 16-byte mmios, we need to support them.  We
can't increase the kvm_run mmio buffer size to 16 bytes without breaking
compatibility, so instead we break the large mmios into two smaller 8-byte
ones.  Since the bus is 64-bit we aren't breaking any atomicity guarantees.

Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7ca831e55186..d1f507567068 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -27,6 +27,10 @@
 
 #include <asm/kvm_host.h>
 
+#ifndef KVM_MMIO_SIZE
+#define KVM_MMIO_SIZE 8
+#endif
+
 /*
  * vcpu->requests bit members
  */
@@ -132,7 +136,8 @@ struct kvm_vcpu {
         int mmio_read_completed;
         int mmio_is_write;
         int mmio_size;
-        unsigned char mmio_data[8];
+        int mmio_index;
+        unsigned char mmio_data[KVM_MMIO_SIZE];
         gpa_t mmio_phys_addr;
 #endif