On 03/06/2012 09:50 AM, Avi Kivity wrote:
The kvmvapic code remaps a section of ROM as RAM to allow the guest to
maintain state there.  It is careful to align the section size to a page
boundary, to avoid creating subpages, but neglects to do the same for
the start address.  These leads to an assert later on when the memory
core tries to create a page which is half RAM and half ROM.

Fix by aligning the start address to a page boundary.

This can be triggered by running qemu-system-x86_64 -enable-kvm -vga none.

Signed-off-by: Avi Kivity<a...@redhat.com>

Tested-by: Anthony Liguori <aligu...@us.ibm.com>

Are you going to do a PULL request or do you want me to apply directly?

Regards,

Anthony Liguori

---
  hw/kvmvapic.c |    4 +++-
  1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/hw/kvmvapic.c b/hw/kvmvapic.c
index 36ccfbc..e8bfeec 100644
--- a/hw/kvmvapic.c
+++ b/hw/kvmvapic.c
@@ -578,8 +578,10 @@ static void vapic_map_rom_writable(VAPICROMState *s)
      rom_size = ram[rom_paddr + 2] * ROM_BLOCK_SIZE;
      s->rom_size = rom_size;

-    /* We need to round up to avoid creating subpages
+    /* We need to round to avoid creating subpages
       * from which we cannot run code. */
+    rom_size += rom_paddr&  ~TARGET_PAGE_MASK;
+    rom_paddr&= TARGET_PAGE_MASK;
      rom_size = TARGET_PAGE_ALIGN(rom_size);

      memory_region_init_alias(&s->rom, "kvmvapic-rom", section.mr, rom_paddr,


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