[PATCH] svm_set_idt() - don't store/get idt to/from LDT save

[PATCH] svm_set_idt() - don't store/get idt to/from LDT save

[Leonard Norrgard]

On AMD processors, executing "shutdown -r now" in a Linux guest actually
reboots the host. While investigating that, I noticed this likely typo.
This patch isn't in itself the complete fix the host reboot, so be
prepared if you test the shutdown command in a Linux guest.

Note: "shutdown -h now" works perfectly and closes the kvm window as
expected.

PS. When I first installed this patch, "shutdown -r now" _didn't_ reboot
the _host_ for about 10 times, instead the guest OOPSed in slightly
different situations. Currently I don't see guest OOPSes, but host reboots.


--- kvm/trunk/kernel/svm.c    2007-01-14 17:29:39.000000000 +0200
+++ kvm-reset/trunk/kernel/svm.c    2007-01-19 15:42:18.000000000 +0200
@@ -680,14 +680,14 @@
 
 static void svm_get_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
-    dt->limit = vcpu->svm->vmcb->save.ldtr.limit;
-    dt->base = vcpu->svm->vmcb->save.ldtr.base;
+    dt->limit = vcpu->svm->vmcb->save.idtr.limit;
+    dt->base = vcpu->svm->vmcb->save.idtr.base;
 }
 
 static void svm_set_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
-    vcpu->svm->vmcb->save.ldtr.limit = dt->limit;
-    vcpu->svm->vmcb->save.ldtr.base = dt->base ;
+    vcpu->svm->vmcb->save.idtr.limit = dt->limit;
+    vcpu->svm->vmcb->save.idtr.base = dt->base ;
 }
 
 static void svm_get_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)


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Re: [PATCH] svm_set_idt() - don't store/get idt to/from LDTsave

[Uri Lublin]

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I've committed this patch.
In addition to the reboot problem, it fixes savevm/loadvm/migration on AMD machines.
Thanks,
    Uri.


-----Original Message-----
From: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org on behalf of Leonard Norrgard
Sent: Fri 19/01/2007 16:49
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: [kvm-devel] [PATCH] svm_set_idt() - don't store/get idt to/from LDTsave
 
On AMD processors, executing "shutdown -r now" in a Linux guest actually
reboots the host. While investigating that, I noticed this likely typo.
This patch isn't in itself the complete fix the host reboot, so be
prepared if you test the shutdown command in a Linux guest.

Note: "shutdown -h now" works perfectly and closes the kvm window as
expected.

PS. When I first installed this patch, "shutdown -r now" _didn't_ reboot
the _host_ for about 10 times, instead the guest OOPSed in slightly
different situations. Currently I don't see guest OOPSes, but host reboots.


--- kvm/trunk/kernel/svm.c    2007-01-14 17:29:39.000000000 +0200
+++ kvm-reset/trunk/kernel/svm.c    2007-01-19 15:42:18.000000000 +0200
@@ -680,14 +680,14 @@
 
 static void svm_get_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
-    dt->limit = vcpu->svm->vmcb->save.ldtr.limit;
-    dt->base = vcpu->svm->vmcb->save.ldtr.base;
+    dt->limit = vcpu->svm->vmcb->save.idtr.limit;
+    dt->base = vcpu->svm->vmcb->save.idtr.base;
 }
 
 static void svm_set_idt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)
 {
-    vcpu->svm->vmcb->save.ldtr.limit = dt->limit;
-    vcpu->svm->vmcb->save.ldtr.base = dt->base ;
+    vcpu->svm->vmcb->save.idtr.limit = dt->limit;
+    vcpu->svm->vmcb->save.idtr.base = dt->base ;
 }
 
 static void svm_get_gdt(struct kvm_vcpu *vcpu, struct descriptor_table *dt)


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