On 10/23/2012 07:52 AM, liu ping fan wrote: > On Mon, Oct 22, 2012 at 6:40 PM, Avi Kivity <a...@redhat.com> wrote: >> On 10/22/2012 11:23 AM, Liu Ping Fan wrote: >>> The broken device state is caused by releasing local lock before acquiring >>> big lock. To fix this issue, we have two choice: >>> 1.use busy flag to protect the state >>> The drawback is that we will introduce independent busy flag for each >>> independent device's logic unit. >>> 2.reload the device's state >>> The drawback is if the call chain is too deep, the action to reload will >>> touch each layer. Also the reloading means to recaculate the >>> intermediate >>> result based on device's regs. >>> >>> This patch adopt the solution 1 to fix the issue. >> >> Doesn't the nested mmio patch detect this? >> > It will only record and fix the issue on one thread. But guest can > touch the emulated device on muti-threads.
I forgot about that. I propose that we merge without a fix. Upstream is broken in the same way; it won't deadlock but it will surely break in some other way if a write can cause another write to be triggered to the same location. When we gain more experience with fine-graining devices we can converge on a good solution. -- error compiling committee.c: too many arguments to function
