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authorPaolo Bonzini <pbonzini@redhat.com>2015-12-02 13:00:54 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2015-12-02 13:12:30 +0100
commit0c2d70c448b7853a91cfa63659aa3cc6630fb9be (patch)
tree7327dbaa1da19f0e397dfef405a45755ff61a92c /translate-all.c
parent21a24302e85024dd7b2a151158adbc1f5dc5c4dd (diff)
translate-all: ensure host page mask is always extended with 1's
Anthony reported that >4GB guests on Xen with 32bit QEMU broke after commit 4ed023c ("Round up RAMBlock sizes to host page sizes", 2015-11-05). In that patch sizes are masked against qemu_host_page_size/mask which are uintptr_t, and thus 32bit on a 32bit QEMU, even though the ram space might be bigger than 4GB on Xen. Since ram_addr_t is not available on user-mode emulation targets, ensure that we get a sign extension when masking away the low bits of the address. Remove the ~10 year old scary comment that the type of these variables is probably wrong, with another equally scary comment. The new comment however does not have "???" in it, which is arguably an improvement. For completeness use the alignment macros in linux-user and bsd-user instead of manually doing an &. linux-user and bsd-user are not affected by the Xen issue, however. Reviewed-by: Juan Quintela <quintela@redhat.com> Reported-by: Anthony PERARD <anthony.perard@citrix.com> Fixes: 4ed023ce2a39ab5812d33cf4d819def168965a7f Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'translate-all.c')
-rw-r--r--translate-all.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/translate-all.c b/translate-all.c
index a940bd2e5e..042a8576ac 100644
--- a/translate-all.c
+++ b/translate-all.c
@@ -118,7 +118,7 @@ typedef struct PageDesc {
#define V_L1_SHIFT (L1_MAP_ADDR_SPACE_BITS - TARGET_PAGE_BITS - V_L1_BITS)
uintptr_t qemu_host_page_size;
-uintptr_t qemu_host_page_mask;
+intptr_t qemu_host_page_mask;
/* The bottom level has pointers to PageDesc */
static void *l1_map[V_L1_SIZE];
@@ -326,14 +326,14 @@ void page_size_init(void)
/* NOTE: we can always suppose that qemu_host_page_size >=
TARGET_PAGE_SIZE */
qemu_real_host_page_size = getpagesize();
- qemu_real_host_page_mask = ~(qemu_real_host_page_size - 1);
+ qemu_real_host_page_mask = -(intptr_t)qemu_real_host_page_size;
if (qemu_host_page_size == 0) {
qemu_host_page_size = qemu_real_host_page_size;
}
if (qemu_host_page_size < TARGET_PAGE_SIZE) {
qemu_host_page_size = TARGET_PAGE_SIZE;
}
- qemu_host_page_mask = ~(qemu_host_page_size - 1);
+ qemu_host_page_mask = -(intptr_t)qemu_host_page_size;
}
static void page_init(void)