On Wed, 19 Mar 2014 17:03:53 -0400 Luiz Capitulino <lcapitul...@redhat.com> wrote:
> Linux guests, when using more than 4GB of RAM, may end up using 1GB pages > to store (kernel) data. When this happens, we're unable to debug a running > Linux kernel with GDB: > > (gdb) p node_data[0]->node_id > Cannot access memory at address 0xffff88013fffd3a0 > (gdb) > > GDB returns this error because x86_cpu_get_phys_page_debug() doesn't support > translating 1GB pages in IA-32e paging mode and returns an error to GDB. > > This commit adds support for 1GB page translation for IA32e paging. Peter, can you pick up this one please? > > Signed-off-by: Luiz capitulino <lcapitul...@redhat.com> > --- > > - I'm proposing this patch for 2.0 because GDB debugging of large Linux > guests is kind of broken > > - Changelog v2: > - Move PS bit handling to if (env->hflags & HF_LMA_MASK) block > - Update changelog > > target-i386/helper.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/target-i386/helper.c b/target-i386/helper.c > index 4f447b8..7cee501 100644 > --- a/target-i386/helper.c > +++ b/target-i386/helper.c > @@ -941,6 +941,14 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr > addr) > pdpe = ldq_phys(cs->as, pdpe_addr); > if (!(pdpe & PG_PRESENT_MASK)) > return -1; > + > + if (pdpe & PG_PSE_MASK) { > + page_size = 1024 * 1024 * 1024; > + pte = pdpe & ~( (page_size - 1) & ~0xfff); > + pte &= ~(PG_NX_MASK | PG_HI_USER_MASK); > + goto out; > + } > + > } else > #endif > { > @@ -993,6 +1001,7 @@ hwaddr x86_cpu_get_phys_page_debug(CPUState *cs, vaddr > addr) > pte = pte & env->a20_mask; > } > > +out: > page_offset = (addr & TARGET_PAGE_MASK) & (page_size - 1); > paddr = (pte & TARGET_PAGE_MASK) + page_offset; > return paddr;