On Tue, Jan 26, 2010 at 10:42 PM, Artyom Tarasenko <atar4q...@googlemail.com> wrote: > 2010/1/26 Blue Swirl <blauwir...@gmail.com>: >> On Tue, Jan 26, 2010 at 7:03 PM, Artyom Tarasenko >> <atar4q...@googlemail.com> wrote: >>> 2010/1/24 Blue Swirl <blauwir...@gmail.com>: >>>> On Sun, Jan 24, 2010 at 2:02 AM, Artyom Tarasenko >>>> <atar4q...@googlemail.com> wrote: >>>>> All solaris versions which currently boot (from cd) regularly produce >>>>> buckets of >>>>> "hsfs_putpage: dirty HSFS page" messages. >>>>> >>>>> High Sierra is a pretty old and stable stuff, so it is possible that >>>>> the code is similar to OpenSolaris. >>>>> I looked in debugger, and the function calls hierarchy looks pretty >>>>> similar. >>>>> >>>>> Now in the OpenSolaris source code there is a nice comment: >>>>> http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/hsfs/hsfs_vnops.c#1758 >>>>> /* >>>>> * Normally pvn_getdirty() should return 0, which >>>>> * impies that it has done the job for us. >>>>> * The shouldn't-happen scenario is when it returns 1. >>>>> * This means that the page has been modified and >>>>> * needs to be put back. >>>>> * Since we can't write on a CD, we fake a failed >>>>> * I/O and force pvn_write_done() to destroy the page. >>>>> */ >>>>> if (pvn_getdirty(pp, flags) == 1) { >>>>> cmn_err(CE_NOTE, >>>>> "hsfs_putpage: dirty HSFS page"); >>>>> >>>>> Now the question: does the problem have to do with qemu caches >>>>> (non-)emulation? >>>>> Can it be that we mark non-dirty pages dirty? Or does qemu always mark >>>>> pages dirty exactly to avoid cache emulation? >>>>> >>>>> Otherwise it means something else goes astray and Solaris guest really >>>>> modifies the pages it shouldn't. >>>>> >>>>> Just wonder what to dig first, MMU or IRQ emulation (the two most >>>>> obvious suspects). >>>> >>>> Maybe the stores via MMU bypass ASIs >>> >>> why bypass stores? What about the non-bypass ones? >> >> Because their use should update the PTE dirty bits. > > update !=always set. Where is it implemented? I guess the code is > shared between multiple architectures. > Is there a way to trace at what point certain page is getting dirty? > > Since it's not the bypass ASIs it must be something else.
target-sparc/helper.c:193 for the page table dirtiness (this is probably what Solaris can detect). There is other kind of dirtiness in exec.c, grep for phys_ram_dirty uses. But this should not be visible to guest.
