From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
This unbreaks guest debugging when the 4th hardware breakpoint used for
guest debugging is a watchpoint of 4 or 8 byte lenght. The 31st bit of
DR7 is set in that case and used to cause a sign extension to the high
word which was breaking the guest state (vm entry failure).
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
target-i386/kvm.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 7e5982b..85edacc 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -1686,7 +1686,7 @@ void kvm_arch_update_guest_debug(CPUState *env, struct kvm_guest_debug *dbg)
dbg->arch.debugreg[n] = hw_breakpoint[n].addr;
dbg->arch.debugreg[7] |= (2 << (n * 2)) |
(type_code[hw_breakpoint[n].type] << (16 + n*4)) |
- (len_code[hw_breakpoint[n].len] << (18 + n*4));
+ ((uint32_t)len_code[hw_breakpoint[n].len] << (18 + n*4));
}
}
/* Legal xcr0 for loading */
--
1.7.2.3
--
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