[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH] kvm: x86: Prevent sign extension of DR7 in guest de
From: |
Jan Kiszka |
Subject: |
[Qemu-devel] [PATCH] kvm: x86: Prevent sign extension of DR7 in guest debugging mode |
Date: |
Mon, 27 Dec 2010 15:58:23 +0100 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
From: Jan Kiszka <address@hidden>
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 <address@hidden>
---
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 9a4bf98..218812a 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -1693,7 +1693,7 @@ 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 */
--
1.7.1
signature.asc
Description: OpenPGP digital signature
- [Qemu-devel] [PATCH] kvm: x86: Prevent sign extension of DR7 in guest debugging mode,
Jan Kiszka <=