[Qemu-devel] [PATCH 1/2] qemu-kvm/cpuid: fix a emulation of guest physical address space

[Xudong Hao]

For 64 bit processor, emulate 40 bits physical address if the host physical
address space >= 40bits, else guest physical is same as host.

Signed-off-by: Xudong Hao <address@hidden>
---
 target-i386/cpu.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 423e009..3a78881 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1584,7 +1584,10 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, 
uint32_t count,
         if (env->cpuid_ext2_features & CPUID_EXT2_LM) {
             /* 64 bit processor */
 /* XXX: The physical address space is limited to 42 bits in exec.c. */
-            *eax = 0x00003028; /* 48 bits virtual, 40 bits physical */
+/* XXX: 40 bits physical if host physical address space >= 40 bits */
+            uint32_t a, b, c, d;
+            host_cpuid(0x80000008, 0, &a, &b, &c, &d);
+            *eax = a < 0x00003028 ? a : 0x00003028;
         } else {
             if (env->cpuid_features & CPUID_PSE36)
                 *eax = 0x00000024; /* 36 bits physical */
-- 
1.5.5