| Message ID | 20100729104145.GA24773@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Thu, Jul 29, 2010 at 01:41:45PM +0300, Gleb Natapov wrote: > Use this one instead. > > On Wed, Jul 28, 2010 at 06:13:22PM +0300, Gleb Natapov wrote: > > It is possible that subpage mmio is registered over existing memory > > page. When this happens "memory" will have real memory address and not > > index into io_mem array so next access to the page will generate > > segfault. It is uncommon to have some part of a page to be accessed as > > memory and some as mmio, but qemu shouldn't crash even when guest does > > stupid things. So lets just pretend that the rest of the page is > > unassigned if guest configure part of the memory page as mmio. > > > > Signed-off-by: Gleb Natapov <gleb@redhat.com> > > diff --git a/exec.c b/exec.c > index 5e9a5b7..53483bc 100644 > --- a/exec.c > +++ b/exec.c > @@ -3362,6 +3362,8 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end, > printf("%s: %p start %08x end %08x idx %08x eidx %08x mem %ld\n", __func__, > mmio, start, end, idx, eidx, memory); > #endif > + if ((memory & ~TARGET_PAGE_MASK) == IO_MEM_RAM) > + memory = IO_MEM_UNASSIGNED; > memory = (memory >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1); > for (; idx <= eidx; idx++) { > mmio->sub_io_index[idx] = memory; Looks good to me.
Thanks, applied. On Thu, Jul 29, 2010 at 9:16 PM, Marcelo Tosatti <mtosatti@redhat.com> wrote: > On Thu, Jul 29, 2010 at 01:41:45PM +0300, Gleb Natapov wrote: >> Use this one instead. >> >> On Wed, Jul 28, 2010 at 06:13:22PM +0300, Gleb Natapov wrote: >> > It is possible that subpage mmio is registered over existing memory >> > page. When this happens "memory" will have real memory address and not >> > index into io_mem array so next access to the page will generate >> > segfault. It is uncommon to have some part of a page to be accessed as >> > memory and some as mmio, but qemu shouldn't crash even when guest does >> > stupid things. So lets just pretend that the rest of the page is >> > unassigned if guest configure part of the memory page as mmio. >> > >> > Signed-off-by: Gleb Natapov <gleb@redhat.com> >> >> diff --git a/exec.c b/exec.c >> index 5e9a5b7..53483bc 100644 >> --- a/exec.c >> +++ b/exec.c >> @@ -3362,6 +3362,8 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end, >> printf("%s: %p start %08x end %08x idx %08x eidx %08x mem %ld\n", __func__, >> mmio, start, end, idx, eidx, memory); >> #endif >> + if ((memory & ~TARGET_PAGE_MASK) == IO_MEM_RAM) >> + memory = IO_MEM_UNASSIGNED; >> memory = (memory >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1); >> for (; idx <= eidx; idx++) { >> mmio->sub_io_index[idx] = memory; > > Looks good to me. > > >
diff --git a/exec.c b/exec.c index 5e9a5b7..53483bc 100644 --- a/exec.c +++ b/exec.c @@ -3362,6 +3362,8 @@ static int subpage_register (subpage_t *mmio, uint32_t start, uint32_t end, printf("%s: %p start %08x end %08x idx %08x eidx %08x mem %ld\n", __func__, mmio, start, end, idx, eidx, memory); #endif + if ((memory & ~TARGET_PAGE_MASK) == IO_MEM_RAM) + memory = IO_MEM_UNASSIGNED; memory = (memory >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1); for (; idx <= eidx; idx++) { mmio->sub_io_index[idx] = memory;