Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 02/06/2013 20:12, Gleb Natapov ha scritto:
On Thu, May 30, 2013 at 04:35:55PM +0200, Paolo Bonzini wrote:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Did I missed unit test patch? :)
I wanted to ask the GSoC student to do it. If it doesn't come in a
couple of weeks, I'll send it.
Paolo
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
-op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
Gleb.
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Mon, Jun 03, 2013 at 08:27:57AM +0200, Paolo Bonzini wrote:
Il 02/06/2013 20:12, Gleb Natapov ha scritto:
On Thu, May 30, 2013 at 04:35:55PM +0200, Paolo Bonzini wrote:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Did I missed unit test patch? :)
I wanted to ask the GSoC student to do it. If it doesn't come in a
couple of weeks, I'll send it.
Which instruction you saw the bug happening with? It this 3.10 regression?
Paolo
Cc: gnata...@redhat.com
Please use my other email :)
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt
*ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
Gleb.
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Gleb.
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 03/06/2013 10:04, Gleb Natapov ha scritto:
On Mon, Jun 03, 2013 at 08:27:57AM +0200, Paolo Bonzini wrote:
Il 02/06/2013 20:12, Gleb Natapov ha scritto:
On Thu, May 30, 2013 at 04:35:55PM +0200, Paolo Bonzini wrote:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Did I missed unit test patch? :)
I wanted to ask the GSoC student to do it. If it doesn't come in a
couple of weeks, I'll send it.
Which instruction you saw the bug happening with? It this 3.10 regression?
cmp $0x1f, %bpl
Like the NOP, it is a regression introduced in the switch of
emulate_invalid_guest_state from 0 to 1.
Paolo
Paolo
Cc: gnata...@redhat.com
Please use my other email :)
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt
*ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
Gleb.
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Thu, May 30, 2013 at 04:35:55PM +0200, Paolo Bonzini wrote:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
Applied to master, thanks.
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
Gleb.
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Thu, May 30, 2013 at 05:34:21PM +0200, Paolo Bonzini wrote:
Il 30/05/2013 16:35, Paolo Bonzini ha scritto:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Well, it is enough but it takes 2 minutes to reach the point where
hardware virtualization is used. It is doing a lot of stuff in
emulation mode because FS and GS have leftovers from the A20 test:
FS = 9300 DPL=0 DS16 [-WA]
GS = 0000 9300 DPL=0 DS16 [-WA]
0x000113be: in $0x92,%al
0x000113c0: or $0x2,%al
0x000113c2: out%al,$0x92
0x000113c4: xor%ax,%ax
0x000113c6: mov%ax,%fs
0x000113c8: dec%ax
0x000113c9: mov%ax,%gs
0x000113cb: inc%ax
0x000113cc: mov%ax,%fs:0x200
0x000113d0: cmp%gs:0x210,%ax
0x000113d5: je 0x113cb
This is 16 bit code that sets them up. So 32bit transition code does not
reload them?
The DPL RPL test fails. Any ideas? Should we introduce a new
intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)?
Paolo
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt
*ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
Gleb.
--
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 03/06/2013 12:25, Gleb Natapov ha scritto:
On Thu, May 30, 2013 at 05:34:21PM +0200, Paolo Bonzini wrote:
Il 30/05/2013 16:35, Paolo Bonzini ha scritto:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Well, it is enough but it takes 2 minutes to reach the point where
hardware virtualization is used. It is doing a lot of stuff in
emulation mode because FS and GS have leftovers from the A20 test:
FS = 9300 DPL=0 DS16 [-WA]
GS = 0000 9300 DPL=0 DS16 [-WA]
0x000113be: in $0x92,%al
0x000113c0: or $0x2,%al
0x000113c2: out%al,$0x92
0x000113c4: xor%ax,%ax
0x000113c6: mov%ax,%fs
0x000113c8: dec%ax
0x000113c9: mov%ax,%gs
0x000113cb: inc%ax
0x000113cc: mov%ax,%fs:0x200
0x000113d0: cmp%gs:0x210,%ax
0x000113d5: je 0x113cb
This is 16 bit code that sets them up. So 32bit transition code does not
reload them?
Yes. It does this:
movw$1, %ax # protected mode (PE) bit
lmsw%ax # This is it!
jmp flush_instr
flush_instr:
xorw%bx, %bx# Flag to indicate a boot
xorl%esi, %esi # Pointer to real-mode code
movw%cs, %si
subw$DELTA_INITSEG, %si
shll$4, %esi# Convert to 32-bit pointer
.byte 0x66, 0xea# prefix + jmpi-opcode
code32: .long 0x1000 # will be set to 0x10
# for big kernels
.word __KERNEL_CS
which jumps to boot/compressed/head.S:
startup_32:
cld
cli
movl$(__KERNEL_DS), %eax
movl%eax, %ds
movl%eax, %es
movl%eax, %ss
and totally ignores fs/gs. Much later there is this (in kernel/head.S):
/*
* We don't really need to load %fs or %gs, but load them anyway
* to kill any stale realmode selectors. This allows execution
* under VT hardware.
*/
movl %eax,%fs
movl %eax,%gs
but the whole decompression is run under emulation.
Paolo
The DPL RPL test fails. Any ideas? Should we introduce a new
intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)?
Paolo
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt
*ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
Gleb.
--
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Thu, May 30, 2013 at 7:34 PM, Paolo Bonzini pbonz...@redhat.com wrote: Il 30/05/2013 17:34, Paolo Bonzini ha scritto: Il 30/05/2013 16:35, Paolo Bonzini ha scritto: The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Well, it is enough but it takes 2 minutes to reach the point where hardware virtualization is used. It is doing a lot of stuff in emulation mode because FS and GS have leftovers from the A20 test: FS = 9300 DPL=0 DS16 [-WA] GS = 0000 9300 DPL=0 DS16 [-WA] 0x000113be: in $0x92,%al 0x000113c0: or $0x2,%al 0x000113c2: out%al,$0x92 0x000113c4: xor%ax,%ax 0x000113c6: mov%ax,%fs 0x000113c8: dec%ax 0x000113c9: mov%ax,%gs 0x000113cb: inc%ax 0x000113cc: mov%ax,%fs:0x200 0x000113d0: cmp%gs:0x210,%ax 0x000113d5: je 0x113cb The DPL RPL test fails. Any ideas? Should we introduce a new intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)? One idea could be to replace invalid descriptors with NULL ones. Then you can intercept this in the #GP handler and trigger emulation for that instruction only. Won't work, vmx won't let you enter in such a configuration. Maybe you can detect the exact code sequence (%eip, some instructions, register state) and clear %fs and %gs. -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Mon, Jun 03, 2013 at 06:42:11PM +0300, Avi Kivity wrote: On Thu, May 30, 2013 at 7:34 PM, Paolo Bonzini pbonz...@redhat.com wrote: Il 30/05/2013 17:34, Paolo Bonzini ha scritto: Il 30/05/2013 16:35, Paolo Bonzini ha scritto: The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Well, it is enough but it takes 2 minutes to reach the point where hardware virtualization is used. It is doing a lot of stuff in emulation mode because FS and GS have leftovers from the A20 test: FS = 9300 DPL=0 DS16 [-WA] GS = 0000 9300 DPL=0 DS16 [-WA] 0x000113be: in $0x92,%al 0x000113c0: or $0x2,%al 0x000113c2: out%al,$0x92 0x000113c4: xor%ax,%ax 0x000113c6: mov%ax,%fs 0x000113c8: dec%ax 0x000113c9: mov%ax,%gs 0x000113cb: inc%ax 0x000113cc: mov%ax,%fs:0x200 0x000113d0: cmp%gs:0x210,%ax 0x000113d5: je 0x113cb The DPL RPL test fails. Any ideas? Should we introduce a new intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)? One idea could be to replace invalid descriptors with NULL ones. Then you can intercept this in the #GP handler and trigger emulation for that instruction only. Won't work, vmx won't let you enter in such a configuration. Why? It is possible to have NULL descriptor in 32bit mode with vmx. But we do not usually intercept #GP while executing 32bit mode, so we will have to track if there is artificial NULL selector and enables #GP interception and then emulate on every #GP. Maybe you can detect the exact code sequence (%eip, some instructions, register state) and clear %fs and %gs. My be we can set dpl to rpl unconditionally on a switch from 16 to 32 bit. The only problem I can see with it is that if a guest enters user mode without explicitly reload the segment it will be accessible by a user mode code, but I am not sure it is well defined what dpl of a 16 bit segment is after transition to 32 bit mode anyway, so it would be crazy to do so. -- Gleb. -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 03/06/2013 18:40, Gleb Natapov ha scritto: Won't work, vmx won't let you enter in such a configuration. Why? It is possible to have NULL descriptor in 32bit mode with vmx. But we do not usually intercept #GP while executing 32bit mode, so we will have to track if there is artificial NULL selector and enables #GP interception and then emulate on every #GP. Yes, that's what I had in mind. Of course for invalid CS you do have to emulate. Maybe you can detect the exact code sequence (%eip, some instructions, register state) and clear %fs and %gs. My be we can set dpl to rpl unconditionally on a switch from 16 to 32 bit. The only problem I can see with it is that if a guest enters user mode without explicitly reload the segment it will be accessible by a user mode code, but I am not sure it is well defined what dpl of a 16 bit segment is after transition to 32 bit mode anyway, so it would be crazy to do so. That too, or just set it to 3. But perhaps the #GP interception wouldn't be too hard. Paolo -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Mon, Jun 03, 2013 at 08:30:18PM +0300, Avi Kivity wrote: On Jun 3, 2013 7:41 PM, Gleb Natapov g...@redhat.com wrote: On Mon, Jun 03, 2013 at 06:42:11PM +0300, Avi Kivity wrote: On Thu, May 30, 2013 at 7:34 PM, Paolo Bonzini pbonz...@redhat.com wrote: Il 30/05/2013 17:34, Paolo Bonzini ha scritto: Il 30/05/2013 16:35, Paolo Bonzini ha scritto: The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Well, it is enough but it takes 2 minutes to reach the point where hardware virtualization is used. It is doing a lot of stuff in emulation mode because FS and GS have leftovers from the A20 test: FS = 9300 DPL=0 DS16 [-WA] GS = 0000 9300 DPL=0 DS16 [-WA] 0x000113be: in $0x92,%al 0x000113c0: or $0x2,%al 0x000113c2: out%al,$0x92 0x000113c4: xor%ax,%ax 0x000113c6: mov%ax,%fs 0x000113c8: dec%ax 0x000113c9: mov%ax,%gs 0x000113cb: inc%ax 0x000113cc: mov%ax,%fs:0x200 0x000113d0: cmp%gs:0x210,%ax 0x000113d5: je 0x113cb The DPL RPL test fails. Any ideas? Should we introduce a new intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)? One idea could be to replace invalid descriptors with NULL ones. Then you can intercept this in the #GP handler and trigger emulation for that instruction only. Won't work, vmx won't let you enter in such a configuration. Why? It is possible to have NULL descriptor in 32bit mode with vmx. But we do not usually intercept #GP while executing 32bit mode, so we will have to track if there is artificial NULL selector and enables #GP interception and then emulate on every #GP. Sorry, was thinking of virtual-8086 mode. It should work. Maybe you can detect the exact code sequence (%eip, some instructions, register state) and clear %fs and %gs. My be we can set dpl to rpl unconditionally on a switch from 16 to 32 bit. The only problem I can see with it is that if a guest enters user mode without explicitly reload the segment it will be accessible by a user mode code, but I am not sure it is well defined what dpl of a 16 bit segment is after transition to 32 bit mode anyway, so it would be crazy to do so. The problem is you cannot detect a segment reload if you do that.Trapping #GP preserves correctness in all cases (at the cost of some complexity). I do not see why I would want to detect reload. Setting segment to NULL has a disadvantage that if guest will read selector it will get wrong value, but may be we can leave selector alone and mark segment unusable. I always wondered what VMX has unusable attribute for, may be this is it. -- Gleb. -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
On Thu, May 30, 2013 at 04:35:55PM +0200, Paolo Bonzini wrote:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Did I missed unit test patch? :)
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
Gleb.
--
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[PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+ highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
1.8.1.4
--
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 30/05/2013 16:35, Paolo Bonzini ha scritto:
The x86-64 extended low-byte registers were fetched correctly from reg,
but not from mod/rm.
This fixes another bug in the boot of RHEL5.9 64-bit, but it is still
not enough.
Well, it is enough but it takes 2 minutes to reach the point where
hardware virtualization is used. It is doing a lot of stuff in
emulation mode because FS and GS have leftovers from the A20 test:
FS = 9300 DPL=0 DS16 [-WA]
GS = 0000 9300 DPL=0 DS16 [-WA]
0x000113be: in $0x92,%al
0x000113c0: or $0x2,%al
0x000113c2: out%al,$0x92
0x000113c4: xor%ax,%ax
0x000113c6: mov%ax,%fs
0x000113c8: dec%ax
0x000113c9: mov%ax,%gs
0x000113cb: inc%ax
0x000113cc: mov%ax,%fs:0x200
0x000113d0: cmp%gs:0x210,%ax
0x000113d5: je 0x113cb
The DPL RPL test fails. Any ideas? Should we introduce a new
intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)?
Paolo
Cc: gnata...@redhat.com
Cc: kvm@vger.kernel.org
Cc: sta...@vger.kernel.org # 3.9
Signed-off-by: Paolo Bonzini pbonz...@redhat.com
---
arch/x86/kvm/emulate.c | 5 -
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index aa68106..028b34f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
ctxt-modrm_seg = VCPU_SREG_DS;
if (ctxt-modrm_mod == 3) {
+ int highbyte_regs = ctxt-rex_prefix == 0;
+
op-type = OP_REG;
op-bytes = (ctxt-d ByteOp) ? 1 : ctxt-op_bytes;
- op-addr.reg = decode_register(ctxt, ctxt-modrm_rm, ctxt-d
ByteOp);
+ op-addr.reg = decode_register(ctxt, ctxt-modrm_rm,
+highbyte_regs (ctxt-d
ByteOp));
if (ctxt-d Sse) {
op-type = OP_XMM;
op-bytes = 16;
--
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Re: [PATCH] KVM: fix sil/dil/bpl/spl in the mod/rm fields
Il 30/05/2013 17:34, Paolo Bonzini ha scritto: Il 30/05/2013 16:35, Paolo Bonzini ha scritto: The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Well, it is enough but it takes 2 minutes to reach the point where hardware virtualization is used. It is doing a lot of stuff in emulation mode because FS and GS have leftovers from the A20 test: FS = 9300 DPL=0 DS16 [-WA] GS = 0000 9300 DPL=0 DS16 [-WA] 0x000113be: in $0x92,%al 0x000113c0: or $0x2,%al 0x000113c2: out%al,$0x92 0x000113c4: xor%ax,%ax 0x000113c6: mov%ax,%fs 0x000113c8: dec%ax 0x000113c9: mov%ax,%gs 0x000113cb: inc%ax 0x000113cc: mov%ax,%fs:0x200 0x000113d0: cmp%gs:0x210,%ax 0x000113d5: je 0x113cb The DPL RPL test fails. Any ideas? Should we introduce a new intermediate value for emulate_invalid_guest_state (0=none, 1=some, 2=full)? One idea could be to replace invalid descriptors with NULL ones. Then you can intercept this in the #GP handler and trigger emulation for that instruction only. Paolo -- To unsubscribe from this list: send the line unsubscribe kvm in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
