Re: Kernel Oops with kvm 66 running WinXP

[Avi Kivity <avi@qumranet.com>]

[-- Attachment #1: Type: text/plain, Size: 500 bytes --]

Michal Ludvig wrote:
>>>
>>> loaded kvm module (kvm-68)
>>> kvm: emulating exchange as write
>>> Unable to handle kernel NULL pointer dereference at 0000000000000000 
>>> RIP:
>>>  [<ffffffff88373b4a>] :kvm:x86_emulate_insn+0x3fa/0x4240
>>
>> Please apply the attached patch, and post 'dmesg | grep writeback'.
>
> writeback: b 01 mordm e0
>

Ah, it only affects pre-npt, so my testing was worthless.  The attached 
patch should fix.

-- 
error compiling committee.c: too many arguments to function


[-- Attachment #2: smsw-fix.patch --]
[-- Type: text/x-patch, Size: 1347 bytes --]

diff --git a/kernel/x86_emulate.c b/kernel/x86_emulate.c
index f2a696d..8a96320 100644
--- a/kernel/x86_emulate.c
+++ b/kernel/x86_emulate.c
@@ -677,8 +677,9 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
 	c->use_modrm_ea = 1;
 
 	if (c->modrm_mod == 3) {
-		c->modrm_val = *(unsigned long *)
-			decode_register(c->modrm_rm, c->regs, c->d & ByteOp);
+		c->modrm_ptr = decode_register(c->modrm_rm,
+					       c->regs, c->d & ByteOp);
+		c->modrm_val = *(unsigned long *)c->modrm_ptr;
 		return rc;
 	}
 
@@ -1005,6 +1006,7 @@ done_prefixes:
 		if ((c->d & ModRM) && c->modrm_mod == 3) {
 			c->src.type = OP_REG;
 			c->src.val = c->modrm_val;
+			c->src.ptr = c->modrm_ptr;
 			break;
 		}
 		c->src.type = OP_MEM;
@@ -1049,6 +1051,7 @@ done_prefixes:
 		if ((c->d & ModRM) && c->modrm_mod == 3) {
 			c->dst.type = OP_REG;
 			c->dst.val = c->dst.orig_val = c->modrm_val;
+			c->dst.ptr = c->modrm_ptr;
 			break;
 		}
 		c->dst.type = OP_MEM;
diff --git a/include/asm-x86/kvm_x86_emulate.h b/include/asm-x86/kvm_x86_emulate.h
index d6337f9..b877bbd 100644
--- a/kernel/include/asm-x86/kvm_x86_emulate.h
+++ b/kernel/include/asm-x86/kvm_x86_emulate.h
@@ -135,6 +135,7 @@ struct decode_cache {
 	u8 modrm_rm;
 	u8 use_modrm_ea;
 	unsigned long modrm_ea;
+	void *modrm_ptr;
 	unsigned long modrm_val;
 	struct fetch_cache fetch;
 };

[-- Attachment #3: Type: text/plain, Size: 320 bytes --]

-------------------------------------------------------------------------
This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
Don't miss this year's exciting event. There's still time to save $100. 
Use priority code J8TL2D2. 
http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone

[-- Attachment #4: Type: text/plain, Size: 158 bytes --]

_______________________________________________
kvm-devel mailing list
kvm-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/kvm-devel