* [PATCH v2 1/4] KVM: x86: Handle TIF_NEED_FPU_LOAD in kvm_{load,put}_guest_fpu()
2020-01-17 19:30 [PATCH v2 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Sean Christopherson
@ 2020-01-17 19:30 ` Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 2/4] KVM: x86: Ensure guest's FPU state is loaded when accessing for emulation Sean Christopherson
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Sean Christopherson @ 2020-01-17 19:30 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Derek Yerger, kernel,
Thomas Lambertz, Rik van Riel, Sebastian Andrzej Siewior,
Borislav Petkov, Dave Hansen, Thomas Gleixner
Handle TIF_NEED_FPU_LOAD similar to how fpu__copy() handles the flag
when duplicating FPU state to a new task struct. TIF_NEED_FPU_LOAD can
be set any time control is transferred out of KVM, be it voluntarily,
e.g. if I/O is triggered during a KVM call to get_user_pages, or
involuntarily, e.g. if softirq runs after an IRQ occurs. Therefore,
KVM must account for TIF_NEED_FPU_LOAD whenever it is (potentially)
accessing CPU FPU state.
Fixes: 5f409e20b7945 ("x86/fpu: Defer FPU state load until return to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/x86.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cf917139de6b..0bbf0110bef7 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8471,12 +8471,26 @@ static int complete_emulated_mmio(struct kvm_vcpu *vcpu)
return 0;
}
+static void kvm_save_current_fpu(struct fpu *fpu)
+{
+ /*
+ * If the target FPU state is not resident in the CPU registers, just
+ * memcpy() from current, else save CPU state directly to the target.
+ */
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ memcpy(&fpu->state, ¤t->thread.fpu.state,
+ fpu_kernel_xstate_size);
+ else
+ copy_fpregs_to_fpstate(fpu);
+}
+
/* Swap (qemu) user FPU context for the guest FPU context. */
static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu)
{
fpregs_lock();
- copy_fpregs_to_fpstate(vcpu->arch.user_fpu);
+ kvm_save_current_fpu(vcpu->arch.user_fpu);
+
/* PKRU is separately restored in kvm_x86_ops->run. */
__copy_kernel_to_fpregs(&vcpu->arch.guest_fpu->state,
~XFEATURE_MASK_PKRU);
@@ -8492,7 +8506,8 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
{
fpregs_lock();
- copy_fpregs_to_fpstate(vcpu->arch.guest_fpu);
+ kvm_save_current_fpu(vcpu->arch.guest_fpu);
+
copy_kernel_to_fpregs(&vcpu->arch.user_fpu->state);
fpregs_mark_activate();
--
2.24.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 2/4] KVM: x86: Ensure guest's FPU state is loaded when accessing for emulation
2020-01-17 19:30 [PATCH v2 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 1/4] KVM: x86: Handle TIF_NEED_FPU_LOAD in kvm_{load,put}_guest_fpu() Sean Christopherson
@ 2020-01-17 19:30 ` Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest" Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors Sean Christopherson
3 siblings, 0 replies; 6+ messages in thread
From: Sean Christopherson @ 2020-01-17 19:30 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Derek Yerger, kernel,
Thomas Lambertz, Rik van Riel, Sebastian Andrzej Siewior,
Borislav Petkov, Dave Hansen, Thomas Gleixner
Lock the FPU regs and reload the current thread's FPU state, which holds
the guest's FPU state, to the CPU registers if necessary prior to
accessing guest FPU state as part of emulation. kernel_fpu_begin() can
be called from softirq context, therefore KVM must ensure softirqs are
disabled (locking the FPU regs disables softirqs) when touching CPU FPU
state.
Note, for all intents and purposes this reverts commit 6ab0b9feb82a7
("x86,kvm: remove KVM emulator get_fpu / put_fpu"), but at the time it
was applied, removing get/put_fpu() was correct. The re-introduction
of {get,put}_fpu() is necessitated by the deferring of FPU state load.
Fixes: 5f409e20b7945 ("x86/fpu: Defer FPU state load until return to userspace")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/emulate.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 952d1a4f4d7e..2a5bed60ce50 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -22,6 +22,7 @@
#include "kvm_cache_regs.h"
#include <asm/kvm_emulate.h>
#include <linux/stringify.h>
+#include <asm/fpu/api.h>
#include <asm/debugreg.h>
#include <asm/nospec-branch.h>
@@ -1075,8 +1076,23 @@ static void fetch_register_operand(struct operand *op)
}
}
+static void emulator_get_fpu(void)
+{
+ fpregs_lock();
+
+ fpregs_assert_state_consistent();
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ switch_fpu_return();
+}
+
+static void emulator_put_fpu(void)
+{
+ fpregs_unlock();
+}
+
static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
{
+ emulator_get_fpu();
switch (reg) {
case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
@@ -1098,11 +1114,13 @@ static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
#endif
default: BUG();
}
+ emulator_put_fpu();
}
static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
int reg)
{
+ emulator_get_fpu();
switch (reg) {
case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
@@ -1124,10 +1142,12 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
#endif
default: BUG();
}
+ emulator_put_fpu();
}
static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
{
+ emulator_get_fpu();
switch (reg) {
case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
@@ -1139,10 +1159,12 @@ static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
default: BUG();
}
+ emulator_put_fpu();
}
static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
{
+ emulator_get_fpu();
switch (reg) {
case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
@@ -1154,6 +1176,7 @@ static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
default: BUG();
}
+ emulator_put_fpu();
}
static int em_fninit(struct x86_emulate_ctxt *ctxt)
@@ -1161,7 +1184,9 @@ static int em_fninit(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
+ emulator_get_fpu();
asm volatile("fninit");
+ emulator_put_fpu();
return X86EMUL_CONTINUE;
}
@@ -1172,7 +1197,9 @@ static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
+ emulator_get_fpu();
asm volatile("fnstcw %0": "+m"(fcw));
+ emulator_put_fpu();
ctxt->dst.val = fcw;
@@ -1186,7 +1213,9 @@ static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
return emulate_nm(ctxt);
+ emulator_get_fpu();
asm volatile("fnstsw %0": "+m"(fsw));
+ emulator_put_fpu();
ctxt->dst.val = fsw;
@@ -4092,8 +4121,12 @@ static int em_fxsave(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
+ emulator_get_fpu();
+
rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state));
+ emulator_put_fpu();
+
if (rc != X86EMUL_CONTINUE)
return rc;
@@ -4136,6 +4169,8 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
if (rc != X86EMUL_CONTINUE)
return rc;
+ emulator_get_fpu();
+
if (size < __fxstate_size(16)) {
rc = fxregs_fixup(&fx_state, size);
if (rc != X86EMUL_CONTINUE)
@@ -4151,6 +4186,8 @@ static int em_fxrstor(struct x86_emulate_ctxt *ctxt)
rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state));
out:
+ emulator_put_fpu();
+
return rc;
}
@@ -5448,7 +5485,9 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
{
int rc;
+ emulator_get_fpu();
rc = asm_safe("fwait");
+ emulator_put_fpu();
if (unlikely(rc != X86EMUL_CONTINUE))
return emulate_exception(ctxt, MF_VECTOR, 0, false);
--
2.24.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest"
2020-01-17 19:30 [PATCH v2 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 1/4] KVM: x86: Handle TIF_NEED_FPU_LOAD in kvm_{load,put}_guest_fpu() Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 2/4] KVM: x86: Ensure guest's FPU state is loaded when accessing for emulation Sean Christopherson
@ 2020-01-17 19:30 ` Sean Christopherson
2020-01-17 19:30 ` [PATCH v2 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors Sean Christopherson
3 siblings, 0 replies; 6+ messages in thread
From: Sean Christopherson @ 2020-01-17 19:30 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Derek Yerger, kernel,
Thomas Lambertz, Rik van Riel, Sebastian Andrzej Siewior,
Borislav Petkov, Dave Hansen, Thomas Gleixner
Reload the current thread's FPU state, which contains the guest's FPU
state, to the CPU registers if necessary during vcpu_enter_guest().
TIF_NEED_FPU_LOAD can be set any time control is transferred out of KVM,
e.g. if I/O is triggered during a KVM call to get_user_pages() or if a
softirq occurs while KVM is scheduled in.
Moving the handling of TIF_NEED_FPU_LOAD from vcpu_enter_guest() to
kvm_arch_vcpu_load(), effectively kvm_sched_in(), papered over a bug
where kvm_put_guest_fpu() failed to account for TIF_NEED_FPU_LOAD. The
easiest way to the kvm_put_guest_fpu() bug was to run with involuntary
preemption enable, thus handling TIF_NEED_FPU_LOAD during kvm_sched_in()
made the bug go away. But, removing the handling in vcpu_enter_guest()
exposed KVM to the rare case of a softirq triggering kernel_fpu_begin()
between vcpu_load() and vcpu_enter_guest().
Now that kvm_{load,put}_guest_fpu() correctly handle TIF_NEED_FPU_LOAD,
revert the commit to both restore the vcpu_enter_guest() behavior and
eliminate the superfluous switch_fpu_return() in kvm_arch_vcpu_load().
Note, leaving the handling in kvm_arch_vcpu_load() isn't wrong per se,
but it is unnecessary, and most critically, makes it extremely difficult
to find bugs such as the kvm_put_guest_fpu() issue due to shrinking the
window where a softirq can corrupt state.
A sample trace triggered by warning if TIF_NEED_FPU_LOAD is set while
vcpu state is loaded:
<IRQ>
gcmaes_crypt_by_sg.constprop.12+0x26e/0x660
? 0xffffffffc024547d
? __qdisc_run+0x83/0x510
? __dev_queue_xmit+0x45e/0x990
? ip_finish_output2+0x1a8/0x570
? fib4_rule_action+0x61/0x70
? fib4_rule_action+0x70/0x70
? fib_rules_lookup+0x13f/0x1c0
? helper_rfc4106_decrypt+0x82/0xa0
? crypto_aead_decrypt+0x40/0x70
? crypto_aead_decrypt+0x40/0x70
? crypto_aead_decrypt+0x40/0x70
? esp_output_tail+0x8f4/0xa5a [esp4]
? skb_ext_add+0xd3/0x170
? xfrm_input+0x7a6/0x12c0
? xfrm4_rcv_encap+0xae/0xd0
? xfrm4_transport_finish+0x200/0x200
? udp_queue_rcv_one_skb+0x1ba/0x460
? udp_unicast_rcv_skb.isra.63+0x72/0x90
? __udp4_lib_rcv+0x51b/0xb00
? ip_protocol_deliver_rcu+0xd2/0x1c0
? ip_local_deliver_finish+0x44/0x50
? ip_local_deliver+0xe0/0xf0
? ip_protocol_deliver_rcu+0x1c0/0x1c0
? ip_rcv+0xbc/0xd0
? ip_rcv_finish_core.isra.19+0x380/0x380
? __netif_receive_skb_one_core+0x7e/0x90
? netif_receive_skb_internal+0x3d/0xb0
? napi_gro_receive+0xed/0x150
? 0xffffffffc0243c77
? net_rx_action+0x149/0x3b0
? __do_softirq+0xe4/0x2f8
? handle_irq_event_percpu+0x6a/0x80
? irq_exit+0xe6/0xf0
? do_IRQ+0x7f/0xd0
? common_interrupt+0xf/0xf
</IRQ>
? irq_entries_start+0x20/0x660
? vmx_get_interrupt_shadow+0x2f0/0x710 [kvm_intel]
? kvm_set_msr_common+0xfc7/0x2380 [kvm]
? recalibrate_cpu_khz+0x10/0x10
? ktime_get+0x3a/0xa0
? kvm_arch_vcpu_ioctl_run+0x107/0x560 [kvm]
? kvm_init+0x6bf/0xd00 [kvm]
? __seccomp_filter+0x7a/0x680
? do_vfs_ioctl+0xa4/0x630
? security_file_ioctl+0x32/0x50
? ksys_ioctl+0x60/0x90
? __x64_sys_ioctl+0x16/0x20
? do_syscall_64+0x5f/0x1a0
? entry_SYSCALL_64_after_hwframe+0x44/0xa9
---[ end trace 9564a1ccad733a90 ]---
This reverts commit e751732486eb3f159089a64d1901992b1357e7cc.
Fixes: e751732486eb3 ("KVM: X86: Fix fpu state crash in kvm guest")
Reported-by: Derek Yerger <derek@djy.llc>
Reported-by: kernel@najdan.com
Cc: Wanpeng Li <wanpengli@tencent.com>
Cc: Thomas Lambertz <mail@thomaslambertz.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/x86.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0bbf0110bef7..815c93cf551b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3458,10 +3458,6 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_x86_ops->vcpu_load(vcpu, cpu);
- fpregs_assert_state_consistent();
- if (test_thread_flag(TIF_NEED_FPU_LOAD))
- switch_fpu_return();
-
/* Apply any externally detected TSC adjustments (due to suspend) */
if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
@@ -8198,8 +8194,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
trace_kvm_entry(vcpu->vcpu_id);
guest_enter_irqoff();
- /* The preempt notifier should have taken care of the FPU already. */
- WARN_ON_ONCE(test_thread_flag(TIF_NEED_FPU_LOAD));
+ fpregs_assert_state_consistent();
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ switch_fpu_return();
if (unlikely(vcpu->arch.switch_db_regs)) {
set_debugreg(0, 7);
--
2.24.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors
2020-01-17 19:30 [PATCH v2 0/4] KVM: x86: TIF_NEED_FPU_LOAD bug fixes Sean Christopherson
` (2 preceding siblings ...)
2020-01-17 19:30 ` [PATCH v2 3/4] KVM: x86: Revert "KVM: X86: Fix fpu state crash in kvm guest" Sean Christopherson
@ 2020-01-17 19:30 ` Sean Christopherson
2020-01-18 21:35 ` Paolo Bonzini
3 siblings, 1 reply; 6+ messages in thread
From: Sean Christopherson @ 2020-01-17 19:30 UTC (permalink / raw)
To: Paolo Bonzini
Cc: Sean Christopherson, Vitaly Kuznetsov, Wanpeng Li, Jim Mattson,
Joerg Roedel, kvm, linux-kernel, Derek Yerger, kernel,
Thomas Lambertz, Rik van Riel, Sebastian Andrzej Siewior,
Borislav Petkov, Dave Hansen, Thomas Gleixner
Remove an unused struct x86_emulate_ctxt * param from low level helpers
used to access guest FPU state. The unused param was left behind by
commit 6ab0b9feb82a ("x86,kvm: remove KVM emulator get_fpu / put_fpu").
No functional change intended.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
arch/x86/kvm/emulate.c | 28 +++++++++++++---------------
1 file changed, 13 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 2a5bed60ce50..3e3b3cd60cce 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1090,7 +1090,7 @@ static void emulator_put_fpu(void)
fpregs_unlock();
}
-static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
+static void read_sse_reg(sse128_t *data, int reg)
{
emulator_get_fpu();
switch (reg) {
@@ -1117,8 +1117,7 @@ static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
emulator_put_fpu();
}
-static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
- int reg)
+static void write_sse_reg(sse128_t *data, int reg)
{
emulator_get_fpu();
switch (reg) {
@@ -1145,7 +1144,7 @@ static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
emulator_put_fpu();
}
-static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
+static void read_mmx_reg(u64 *data, int reg)
{
emulator_get_fpu();
switch (reg) {
@@ -1162,7 +1161,7 @@ static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
emulator_put_fpu();
}
-static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
+static void write_mmx_reg(u64 *data, int reg)
{
emulator_get_fpu();
switch (reg) {
@@ -1234,7 +1233,7 @@ static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
op->type = OP_XMM;
op->bytes = 16;
op->addr.xmm = reg;
- read_sse_reg(ctxt, &op->vec_val, reg);
+ read_sse_reg(&op->vec_val, reg);
return;
}
if (ctxt->d & Mmx) {
@@ -1285,7 +1284,7 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt,
op->type = OP_XMM;
op->bytes = 16;
op->addr.xmm = ctxt->modrm_rm;
- read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
+ read_sse_reg(&op->vec_val, ctxt->modrm_rm);
return rc;
}
if (ctxt->d & Mmx) {
@@ -1862,10 +1861,10 @@ static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
op->bytes * op->count);
break;
case OP_XMM:
- write_sse_reg(ctxt, &op->vec_val, op->addr.xmm);
+ write_sse_reg(&op->vec_val, op->addr.xmm);
break;
case OP_MM:
- write_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
+ write_mmx_reg(&op->mm_val, op->addr.mm);
break;
case OP_NONE:
/* no writeback */
@@ -5495,11 +5494,10 @@ static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE;
}
-static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt,
- struct operand *op)
+static void fetch_possible_mmx_operand(struct operand *op)
{
if (op->type == OP_MM)
- read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
+ read_mmx_reg(&op->mm_val, op->addr.mm);
}
static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
@@ -5578,10 +5576,10 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
* Now that we know the fpu is exception safe, we can fetch
* operands from it.
*/
- fetch_possible_mmx_operand(ctxt, &ctxt->src);
- fetch_possible_mmx_operand(ctxt, &ctxt->src2);
+ fetch_possible_mmx_operand(&ctxt->src);
+ fetch_possible_mmx_operand(&ctxt->src2);
if (!(ctxt->d & Mov))
- fetch_possible_mmx_operand(ctxt, &ctxt->dst);
+ fetch_possible_mmx_operand(&ctxt->dst);
}
if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) {
--
2.24.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors
2020-01-17 19:30 ` [PATCH v2 4/4] KVM: x86: Remove unused ctxt param from emulator's FPU accessors Sean Christopherson
@ 2020-01-18 21:35 ` Paolo Bonzini
0 siblings, 0 replies; 6+ messages in thread
From: Paolo Bonzini @ 2020-01-18 21:35 UTC (permalink / raw)
To: Sean Christopherson
Cc: Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel, kvm,
linux-kernel, Derek Yerger, kernel, Thomas Lambertz,
Rik van Riel, Sebastian Andrzej Siewior, Borislav Petkov,
Dave Hansen, Thomas Gleixner
On 17/01/20 20:30, Sean Christopherson wrote:
> Remove an unused struct x86_emulate_ctxt * param from low level helpers
> used to access guest FPU state. The unused param was left behind by
> commit 6ab0b9feb82a ("x86,kvm: remove KVM emulator get_fpu / put_fpu").
>
> No functional change intended.
Makes sense since the new implementation of emulator_get/put_fpu can be
considered generic, and therefore it's okay not to tie it to ctxt->ops.
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 6+ messages in thread