On 10/23/2012 11:32 AM, liu ping fan wrote: > On Tue, Oct 23, 2012 at 5:07 PM, Jan Kiszka <jan.kis...@siemens.com> wrote: >> On 2012-10-23 07:52, 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. >> >> Sorry, what does that mean? A second VCPU accessing the device will >> simply be ignored when it races with another VCPU? Specifically >> > Yes, just ignored. For device which support many logic in parallel, > it should use independent busy flag for each logic
We don't actually know that e1000 doesn't. Why won't writing into different registers in parallel work? -- error compiling committee.c: too many arguments to function
