linux-kernel - [PATCH 44/47] KVM: Use kvm_{read,write}_guest_virt() to read and write segment descriptors

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1251282609-12835-45-git-send-email-avi@redhat.com>
Date:	Wed, 26 Aug 2009 13:30:06 +0300
From:	Avi Kivity <avi@...hat.com>
To:	kvm@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH 44/47] KVM: Use kvm_{read,write}_guest_virt() to read and write segment descriptors

From: Mikhail Ershov <Mike.Ershov@...il.com>

Segment descriptors tables can be placed on two non-contiguous pages.
This patch makes reading segment descriptors by linear address.

Signed-off-by: Mikhail Ershov <Mike.Ershov@...il.com>
Signed-off-by: Avi Kivity <avi@...hat.com>
---
 arch/x86/kvm/x86.c |   10 ++--------
 1 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c0e9427..59a8ba4 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4021,7 +4021,6 @@ 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;
 
@@ -4031,16 +4030,13 @@ 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;
 
@@ -4048,9 +4044,7 @@ 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,
-- 
1.6.4.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/