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[Qemu-devel] [PATCH 01/15] kvm: x86: Save/restore FPU OP, IP and DP
From: |
Marcelo Tosatti |
Subject: |
[Qemu-devel] [PATCH 01/15] kvm: x86: Save/restore FPU OP, IP and DP |
Date: |
Tue, 21 Jun 2011 14:07:50 -0300 |
From: Jan Kiszka <address@hidden>
These FPU states are properly maintained by KVM but not yet by TCG. So
far we unconditionally set them to 0 in the guest which may cause
state corruptions, though not with modern guests.
To avoid breaking backward migration, use a conditional subsection that
is only written if any of the three fields is non-zero. The guest's
FNINIT clears them frequently, and cleared IA32_MISC_ENABLE MSR[2]
reduces the probability of non-zero values further so that this
subsection is not expected to restrict migration in any common scenario.
Signed-off-by: Jan Kiszka <address@hidden>
Signed-off-by: Avi Kivity <address@hidden>
---
target-i386/cpu.h | 4 ++++
target-i386/kvm.c | 20 +++++++++++++++-----
target-i386/machine.c | 23 +++++++++++++++++++++++
3 files changed, 42 insertions(+), 5 deletions(-)
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 9c3340d..cdf68ff 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -641,6 +641,10 @@ typedef struct CPUX86State {
uint16_t fpuc;
uint8_t fptags[8]; /* 0 = valid, 1 = empty */
FPReg fpregs[8];
+ /* KVM-only so far */
+ uint16_t fpop;
+ uint64_t fpip;
+ uint64_t fpdp;
/* emulator internal variables */
float_status fp_status;
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 1ae2d61..16e8213 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -753,6 +753,9 @@ static int kvm_put_fpu(CPUState *env)
fpu.fsw = env->fpus & ~(7 << 11);
fpu.fsw |= (env->fpstt & 7) << 11;
fpu.fcw = env->fpuc;
+ fpu.last_opcode = env->fpop;
+ fpu.last_ip = env->fpip;
+ fpu.last_dp = env->fpdp;
for (i = 0; i < 8; ++i) {
fpu.ftwx |= (!env->fptags[i]) << i;
}
@@ -778,7 +781,7 @@ static int kvm_put_xsave(CPUState *env)
#ifdef KVM_CAP_XSAVE
int i, r;
struct kvm_xsave* xsave;
- uint16_t cwd, swd, twd, fop;
+ uint16_t cwd, swd, twd;
if (!kvm_has_xsave()) {
return kvm_put_fpu(env);
@@ -786,7 +789,7 @@ static int kvm_put_xsave(CPUState *env)
xsave = qemu_memalign(4096, sizeof(struct kvm_xsave));
memset(xsave, 0, sizeof(struct kvm_xsave));
- cwd = swd = twd = fop = 0;
+ cwd = swd = twd = 0;
swd = env->fpus & ~(7 << 11);
swd |= (env->fpstt & 7) << 11;
cwd = env->fpuc;
@@ -794,7 +797,9 @@ static int kvm_put_xsave(CPUState *env)
twd |= (!env->fptags[i]) << i;
}
xsave->region[0] = (uint32_t)(swd << 16) + cwd;
- xsave->region[1] = (uint32_t)(fop << 16) + twd;
+ xsave->region[1] = (uint32_t)(env->fpop << 16) + twd;
+ memcpy(&xsave->region[XSAVE_CWD_RIP], &env->fpip, sizeof(env->fpip));
+ memcpy(&xsave->region[XSAVE_CWD_RDP], &env->fpdp, sizeof(env->fpdp));
memcpy(&xsave->region[XSAVE_ST_SPACE], env->fpregs,
sizeof env->fpregs);
memcpy(&xsave->region[XSAVE_XMM_SPACE], env->xmm_regs,
@@ -970,6 +975,9 @@ static int kvm_get_fpu(CPUState *env)
env->fpstt = (fpu.fsw >> 11) & 7;
env->fpus = fpu.fsw;
env->fpuc = fpu.fcw;
+ env->fpop = fpu.last_opcode;
+ env->fpip = fpu.last_ip;
+ env->fpdp = fpu.last_dp;
for (i = 0; i < 8; ++i) {
env->fptags[i] = !((fpu.ftwx >> i) & 1);
}
@@ -985,7 +993,7 @@ static int kvm_get_xsave(CPUState *env)
#ifdef KVM_CAP_XSAVE
struct kvm_xsave* xsave;
int ret, i;
- uint16_t cwd, swd, twd, fop;
+ uint16_t cwd, swd, twd;
if (!kvm_has_xsave()) {
return kvm_get_fpu(env);
@@ -1001,13 +1009,15 @@ static int kvm_get_xsave(CPUState *env)
cwd = (uint16_t)xsave->region[0];
swd = (uint16_t)(xsave->region[0] >> 16);
twd = (uint16_t)xsave->region[1];
- fop = (uint16_t)(xsave->region[1] >> 16);
+ env->fpop = (uint16_t)(xsave->region[1] >> 16);
env->fpstt = (swd >> 11) & 7;
env->fpus = swd;
env->fpuc = cwd;
for (i = 0; i < 8; ++i) {
env->fptags[i] = !((twd >> i) & 1);
}
+ memcpy(&env->fpip, &xsave->region[XSAVE_CWD_RIP], sizeof(env->fpip));
+ memcpy(&env->fpdp, &xsave->region[XSAVE_CWD_RDP], sizeof(env->fpdp));
env->mxcsr = xsave->region[XSAVE_MXCSR];
memcpy(env->fpregs, &xsave->region[XSAVE_ST_SPACE],
sizeof env->fpregs);
diff --git a/target-i386/machine.c b/target-i386/machine.c
index bbeae88..d22a731 100644
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -290,6 +290,26 @@ static const VMStateDescription vmstate_async_pf_msr = {
}
};
+static bool fpop_ip_dp_needed(void *opaque)
+{
+ CPUState *env = opaque;
+
+ return env->fpop != 0 || env->fpip != 0 || env->fpdp != 0;
+}
+
+static const VMStateDescription vmstate_fpop_ip_dp = {
+ .name = "cpu/fpop_ip_dp",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .fields = (VMStateField []) {
+ VMSTATE_UINT16_V(fpop, CPUState, 13),
+ VMSTATE_UINT64_V(fpip, CPUState, 13),
+ VMSTATE_UINT64_V(fpdp, CPUState, 13),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
static const VMStateDescription vmstate_cpu = {
.name = "cpu",
.version_id = CPU_SAVE_VERSION,
@@ -398,6 +418,9 @@ static const VMStateDescription vmstate_cpu = {
.vmsd = &vmstate_async_pf_msr,
.needed = async_pf_msr_needed,
} , {
+ .vmsd = &vmstate_fpop_ip_dp,
+ .needed = fpop_ip_dp_needed,
+ } , {
/* empty */
}
}
--
1.7.5.4
- [Qemu-devel] [PATCH 00/15] [PULL] qemu-kvm.git uq/master queue, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 06/15] kvm: ppc: Drop CONFIG_KVM_PPC_PVR, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 12/15] kvm: x86: Pass KVMState to kvm_arch_get_supported_cpuid, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 07/15] kvm: Drop useless zero-initializations, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 10/15] kvm: ppc: Drop KVM_CAP build dependencies, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 08/15] kvm: Drop KVM_CAP build dependencies, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 11/15] kvm: Clean up stubs, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 13/15] Remove unneeded kvm.h from cpu-exec.c, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 05/15] kvm: Drop CONFIG_KVM_PARA, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 14/15] KVM: Fix XSAVE feature bit enumeration, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 01/15] kvm: x86: Save/restore FPU OP, IP and DP,
Marcelo Tosatti <=
- [Qemu-devel] [PATCH 04/15] Switch build system to accompanied kernel headers, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 02/15] Add kernel header update script, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 15/15] kvm: fix FPU state subsection, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 09/15] kvm: x86: Drop KVM_CAP build dependencies, Marcelo Tosatti, 2011/06/21
- [Qemu-devel] [PATCH 03/15] Import kernel headers, Marcelo Tosatti, 2011/06/21
- Re: [Qemu-devel] [PATCH 00/15] [PULL] qemu-kvm.git uq/master queue, Anthony Liguori, 2011/06/22