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authorAlexander Graf <agraf@suse.de>2014-11-07 22:12:48 +0100
committerAlexander Graf <agraf@suse.de>2014-11-20 14:52:01 +0100
commitf2a64032a14c642d0ddc9a7a846fc3d737deede5 (patch)
parent3ade1a055c9ac6c351a008703e30fb831f23b941 (diff)
kvm: Fix memory slot page alignment logic
Memory slots have to be page aligned to get entered into KVM. There is existing logic that tries to ensure that we pad memory slots that are not page aligned to the biggest region that would still fit in the alignment requirements. Unfortunately, that logic is broken. It tries to calculate the start offset based on the region size. Fix up the logic to do the thing it was intended to do and document it properly in the comment above it. With this patch applied, I can successfully run an e500 guest with more than 3GB RAM (at which point RAM starts overlapping subpage memory regions). Cc: qemu-stable@nongnu.org Signed-off-by: Alexander Graf <agraf@suse.de>
1 files changed, 4 insertions, 2 deletions
diff --git a/kvm-all.c b/kvm-all.c
index 44a5e724ea..596e7ce6c3 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -634,8 +634,10 @@ static void kvm_set_phys_mem(MemoryRegionSection *section, bool add)
unsigned delta;
/* kvm works in page size chunks, but the function may be called
- with sub-page size and unaligned start address. */
- delta = TARGET_PAGE_ALIGN(size) - size;
+ with sub-page size and unaligned start address. Pad the start
+ address to next and truncate size to previous page boundary. */
+ delta = (TARGET_PAGE_SIZE - (start_addr & ~TARGET_PAGE_MASK));
+ delta &= ~TARGET_PAGE_MASK;
if (delta > size) {