Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-13 Thread Xiao Guangrong
On 12/14/2012 07:02 AM, Marcelo Tosatti wrote: >>> Same comment as before: the only case where it should not attempt to >>> emulate is when there is a condition which makes it impossible to fix >>> (the information is available to detect that condition). >>> >>> The earlier suggestion >>> >>>

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-13 Thread Marcelo Tosatti
On Thu, Dec 13, 2012 at 03:29:21AM +0800, Xiao Guangrong wrote: > On 12/12/2012 09:09 AM, Marcelo Tosatti wrote: > > On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: > >> The current reexecute_instruction can not well detect the failed > >> instruction > >> emulation. It allows

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-13 Thread Marcelo Tosatti
On Thu, Dec 13, 2012 at 03:29:21AM +0800, Xiao Guangrong wrote: On 12/12/2012 09:09 AM, Marcelo Tosatti wrote: On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: The current reexecute_instruction can not well detect the failed instruction emulation. It allows guest to retry

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-13 Thread Xiao Guangrong
On 12/14/2012 07:02 AM, Marcelo Tosatti wrote: Same comment as before: the only case where it should not attempt to emulate is when there is a condition which makes it impossible to fix (the information is available to detect that condition). The earlier suggestion How about recording

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-12 Thread Xiao Guangrong
On 12/12/2012 09:09 AM, Marcelo Tosatti wrote: > On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: >> The current reexecute_instruction can not well detect the failed instruction >> emulation. It allows guest to retry all the instructions except it accesses >> on error pfn >> >> For

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-12 Thread Xiao Guangrong
On 12/12/2012 09:09 AM, Marcelo Tosatti wrote: On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: The current reexecute_instruction can not well detect the failed instruction emulation. It allows guest to retry all the instructions except it accesses on error pfn For example,

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-11 Thread Marcelo Tosatti
On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: > The current reexecute_instruction can not well detect the failed instruction > emulation. It allows guest to retry all the instructions except it accesses > on error pfn > > For example, some cases are nested-write-protect - if the

Re: [PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-11 Thread Marcelo Tosatti
On Mon, Dec 10, 2012 at 05:14:47PM +0800, Xiao Guangrong wrote: The current reexecute_instruction can not well detect the failed instruction emulation. It allows guest to retry all the instructions except it accesses on error pfn For example, some cases are nested-write-protect - if the page

[PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-10 Thread Xiao Guangrong
The current reexecute_instruction can not well detect the failed instruction emulation. It allows guest to retry all the instructions except it accesses on error pfn For example, some cases are nested-write-protect - if the page we want to write is used as PDE but it chains to itself. Under this

[PATCH v2 5/5] KVM: x86: improve reexecute_instruction

2012-12-10 Thread Xiao Guangrong
The current reexecute_instruction can not well detect the failed instruction emulation. It allows guest to retry all the instructions except it accesses on error pfn For example, some cases are nested-write-protect - if the page we want to write is used as PDE but it chains to itself. Under this