[patch] wrong tlb flush order

[patch] wrong tlb flush order

[Shaohua Li]

Sounds like a obvious bug to me. Other places doing tlb flush do the right thing.

Signed-off-by: Shaohua Li <shaohua.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Index: kvm-28/kernel/mmu.c
===================================================================
--- kvm-28.orig/kernel/mmu.c	2007-06-20 16:52:46.000000000 +0800
+++ kvm-28/kernel/mmu.c	2007-06-20 17:10:02.000000000 +0800
@@ -441,8 +441,8 @@
 		BUG_ON(!(*spte & PT_WRITABLE_MASK));
 		rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
 		rmap_remove(vcpu, spte);
-		kvm_flush_remote_tlbs(vcpu->kvm);
 		set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
+		kvm_flush_remote_tlbs(vcpu->kvm);
 	}
 }
 

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

Re: [patch] wrong tlb flush order

[Avi Kivity]

Shaohua Li wrote:
> Sounds like a obvious bug to me. Other places doing tlb flush do the right thing.
>   

Right.  Applied, thanks.

-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

Re: [patch] wrong tlb flush order

[Nakajima, Jun]

Avi Kivity wrote:
> Shaohua Li wrote:
> > Sounds like a obvious bug to me. Other places doing tlb flush do the
right
> > thing. 
> > 
> 
> Right.  Applied, thanks.

BTW,

The current VMX code does not make sense to me:

static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
{
	vmcs_writel(GUEST_CR3, vmcs_readl(GUEST_CR3));
}

Jun
---
Intel Open Source Technology Center

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

Re: [patch] wrong tlb flush order

[Li, Xin B]

>
>BTW,
>
>The current VMX code does not make sense to me:
>
>static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
>{
>	vmcs_writel(GUEST_CR3, vmcs_readl(GUEST_CR3));
>}
>

The point is, vmexits will invalidate all TLB entries on Intel VT
processor today.
-Xin 

-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/

Re: [patch] wrong tlb flush order

[Avi Kivity]

Li, Xin B wrote:
>> BTW,
>>
>> The current VMX code does not make sense to me:
>>
>> static void vmx_flush_tlb(struct kvm_vcpu *vcpu)
>> {
>> 	vmcs_writel(GUEST_CR3, vmcs_readl(GUEST_CR3));
>> }
>>
>>     
>
> The point is, vmexits will invalidate all TLB entries on Intel VT
> processor today.
>   

Yes.  This was based on some text in the manual that I can't find 
anymore.  I long suspected that it is unnecessary.

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


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/