x86: use kvm_read/write_guest_virt for reading and writing segment descriptors

Commit Message

Mikhail Ershov Aug. 19, 2009, 10:42 a.m. UTC

The patch is in attachment.

2009/8/16 Avi Kivity <[e-mail]>:
> On 08/10/2009 08:11 PM, Mikhail Ershov wrote:
>>
>> Descriptor table can be placed on two non-contiguous pages.
>> It is better to read descriptor by linear address.
>>
>
> Patch is good, but is whitespace-corrupted.  Please send as an attachment
> (or using git-send-email).
>
> Make sure the attachment is plain/text so mail clients can display it
> inline.
>
> --
> error compiling committee.c: too many arguments to function
>
>

Comments

Avi Kivity Aug. 19, 2009, 10:45 a.m. UTC | #1

On 08/19/2009 01:42 PM, Mikhail Ershov wrote:
> The patch is in attachment.
>
>    

Applied, thanks.

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 52d5d72..aa2dd12 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4017,7 +4017,6 @@  static void get_segment_descriptor_dtable(struct kvm_vcpu *vcpu,
 static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 					 struct desc_struct *seg_desc)
 {
-	gpa_t gpa;
 	struct descriptor_table dtable;
 	u16 index = selector >> 3;
 
@@ -4027,16 +4026,13 @@  static int load_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 		kvm_queue_exception_e(vcpu, GP_VECTOR, selector & 0xfffc);
 		return 1;
 	}
-	gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
-	gpa += index * 8;
-	return kvm_read_guest(vcpu->kvm, gpa, seg_desc, 8);
+	return kvm_read_guest_virt(dtable.base + index*8, seg_desc, sizeof(*seg_desc), vcpu);
 }
 
 /* allowed just for 8 bytes segments */
 static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 					 struct desc_struct *seg_desc)
 {
-	gpa_t gpa;
 	struct descriptor_table dtable;
 	u16 index = selector >> 3;
 
@@ -4044,9 +4040,7 @@  static int save_guest_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 
 	if (dtable.limit < index * 8 + 7)
 		return 1;
-	gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, dtable.base);
-	gpa += index * 8;
-	return kvm_write_guest(vcpu->kvm, gpa, seg_desc, 8);
+	return kvm_write_guest_virt(dtable.base + index*8, seg_desc, sizeof(*seg_desc), vcpu);
 }
 
 static u32 get_tss_base_addr(struct kvm_vcpu *vcpu,