* [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices
@ 2010-06-30 4:25 Sheng Yang
2010-06-30 4:25 ` [PATCH v6 2/2] KVM: Using workqueue for WBINVD Sheng Yang
2010-06-30 16:34 ` [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Marcelo Tosatti
0 siblings, 2 replies; 4+ messages in thread
From: Sheng Yang @ 2010-06-30 4:25 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti
Cc: Jan Kiszka, Joerg Roedel, kvm, Sheng Yang, Yaozu (Eddie) Dong
Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
CLFLUSH, we need to maintain data consistency either by:
1: flushing cache (wbinvd) when the guest is scheduled out if there is no
wbinvd exit, or
2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 6 +++++
arch/x86/kvm/emulate.c | 5 +++-
arch/x86/kvm/svm.c | 7 ++++++
arch/x86/kvm/vmx.c | 10 ++++++++-
arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++++++++++
5 files changed, 67 insertions(+), 2 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a57cdea..2bda624 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -15,6 +15,7 @@
#include <linux/mm.h>
#include <linux/mmu_notifier.h>
#include <linux/tracepoint.h>
+#include <linux/cpumask.h>
#include <linux/kvm.h>
#include <linux/kvm_para.h>
@@ -358,6 +359,8 @@ struct kvm_vcpu_arch {
/* fields used by HYPER-V emulation */
u64 hv_vapic;
+
+ cpumask_var_t wbinvd_dirty_mask;
};
struct kvm_arch {
@@ -514,6 +517,8 @@ struct kvm_x86_ops {
void (*set_supported_cpuid)(u32 func, struct kvm_cpuid_entry2 *entry);
+ bool (*has_wbinvd_exit)(void);
+
const struct trace_print_flags *exit_reasons_str;
};
@@ -571,6 +576,7 @@ void kvm_emulate_cpuid(struct kvm_vcpu *vcpu);
int kvm_emulate_halt(struct kvm_vcpu *vcpu);
int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address);
int emulate_clts(struct kvm_vcpu *vcpu);
+int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu);
void kvm_get_segment(struct kvm_vcpu *vcpu, struct kvm_segment *var, int seg);
int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector, int seg);
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index abb8cec..e8bdddc 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3138,8 +3138,11 @@ twobyte_insn:
emulate_clts(ctxt->vcpu);
c->dst.type = OP_NONE;
break;
- case 0x08: /* invd */
case 0x09: /* wbinvd */
+ kvm_emulate_wbinvd(ctxt->vcpu);
+ c->dst.type = OP_NONE;
+ break;
+ case 0x08: /* invd */
case 0x0d: /* GrpP (prefetch) */
case 0x18: /* Grp16 (prefetch/nop) */
c->dst.type = OP_NONE;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 587b99d..56c9b6b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -3424,6 +3424,11 @@ static bool svm_rdtscp_supported(void)
return false;
}
+static bool svm_has_wbinvd_exit(void)
+{
+ return true;
+}
+
static void svm_fpu_deactivate(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -3508,6 +3513,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.rdtscp_supported = svm_rdtscp_supported,
.set_supported_cpuid = svm_set_supported_cpuid,
+
+ .has_wbinvd_exit = svm_has_wbinvd_exit,
};
static int __init svm_init(void)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e565689..806ab12 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -412,6 +412,12 @@ static inline bool cpu_has_virtual_nmis(void)
return vmcs_config.pin_based_exec_ctrl & PIN_BASED_VIRTUAL_NMIS;
}
+static inline bool cpu_has_vmx_wbinvd_exit(void)
+{
+ return vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_WBINVD_EXITING;
+}
+
static inline bool report_flexpriority(void)
{
return flexpriority_enabled;
@@ -3400,7 +3406,7 @@ static int handle_invlpg(struct kvm_vcpu *vcpu)
static int handle_wbinvd(struct kvm_vcpu *vcpu)
{
skip_emulated_instruction(vcpu);
- /* TODO: Add support for VT-d/pass-through device */
+ kvm_emulate_wbinvd(vcpu);
return 1;
}
@@ -4350,6 +4356,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.rdtscp_supported = vmx_rdtscp_supported,
.set_supported_cpuid = vmx_set_supported_cpuid,
+
+ .has_wbinvd_exit = cpu_has_vmx_wbinvd_exit,
};
static int __init vmx_init(void)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d0b9252..eea75f5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1783,8 +1783,28 @@ out:
return r;
}
+static void wbinvd_ipi(void *garbage)
+{
+ wbinvd();
+}
+
+static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
+{
+ return vcpu->kvm->arch.iommu_domain &&
+ !(vcpu->kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY);
+}
+
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
+ /* Address WBINVD may be executed by guest */
+ if (need_emulate_wbinvd(vcpu)) {
+ if (kvm_x86_ops->has_wbinvd_exit())
+ cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
+ else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
+ smp_call_function_single(vcpu->cpu,
+ wbinvd_ipi, NULL, 1);
+ }
+
kvm_x86_ops->vcpu_load(vcpu, cpu);
if (unlikely(per_cpu(cpu_tsc_khz, cpu) == 0)) {
unsigned long khz = cpufreq_quick_get(cpu);
@@ -3650,6 +3670,21 @@ int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
return X86EMUL_CONTINUE;
}
+int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
+{
+ if (!need_emulate_wbinvd(vcpu))
+ return X86EMUL_CONTINUE;
+
+ if (kvm_x86_ops->has_wbinvd_exit()) {
+ smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
+ wbinvd_ipi, NULL, 1);
+ cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
+ }
+ wbinvd();
+ return X86EMUL_CONTINUE;
+}
+EXPORT_SYMBOL_GPL(kvm_emulate_wbinvd);
+
int emulate_clts(struct kvm_vcpu *vcpu)
{
kvm_x86_ops->set_cr0(vcpu, kvm_read_cr0_bits(vcpu, ~X86_CR0_TS));
@@ -5255,6 +5290,7 @@ void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
vcpu->arch.time_page = NULL;
}
+ free_cpumask_var(vcpu->arch.wbinvd_dirty_mask);
fx_free(vcpu);
kvm_x86_ops->vcpu_free(vcpu);
}
@@ -5384,7 +5420,12 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
}
vcpu->arch.mcg_cap = KVM_MAX_MCE_BANKS;
+ if (!zalloc_cpumask_var(&vcpu->arch.wbinvd_dirty_mask, GFP_KERNEL))
+ goto fail_free_mce_banks;
+
return 0;
+fail_free_mce_banks:
+ kfree(vcpu->arch.mce_banks);
fail_free_lapic:
kvm_free_lapic(vcpu);
fail_mmu_destroy:
--
1.7.0.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH v6 2/2] KVM: Using workqueue for WBINVD
2010-06-30 4:25 [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Sheng Yang
@ 2010-06-30 4:25 ` Sheng Yang
2010-06-30 16:41 ` Marcelo Tosatti
2010-06-30 16:34 ` [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Marcelo Tosatti
1 sibling, 1 reply; 4+ messages in thread
From: Sheng Yang @ 2010-06-30 4:25 UTC (permalink / raw)
To: Avi Kivity, Marcelo Tosatti; +Cc: Jan Kiszka, Joerg Roedel, kvm, Sheng Yang
It would buy us the ability to schedule compared to smp_call_function().
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
---
But I am not sure if it worth the complexity. Anyway WBINVD itself can't be
interrupted, so the benefit should come to the caller cpu I think. And that
would extended the waiting time for the caller cpu, for we still need to wait
other cpus to complete their works.
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/x86.c | 35 ++++++++++++++++++++++++++++-------
2 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2bda624..6e0b793 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -16,6 +16,7 @@
#include <linux/mmu_notifier.h>
#include <linux/tracepoint.h>
#include <linux/cpumask.h>
+#include <linux/workqueue.h>
#include <linux/kvm.h>
#include <linux/kvm_para.h>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index eea75f5..13f7c88 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -153,6 +153,9 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
u64 __read_mostly host_xcr0;
+static struct workqueue_struct *wbinvd_wq;
+static DEFINE_PER_CPU(struct work_struct, wbinvd_work);
+
static inline u32 bit(int bitno)
{
return 1 << (bitno & 31);
@@ -1783,7 +1786,7 @@ out:
return r;
}
-static void wbinvd_ipi(void *garbage)
+static void wbinvd_do_work(struct work_struct *work)
{
wbinvd();
}
@@ -1800,9 +1803,11 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
if (need_emulate_wbinvd(vcpu)) {
if (kvm_x86_ops->has_wbinvd_exit())
cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
- else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
- smp_call_function_single(vcpu->cpu,
- wbinvd_ipi, NULL, 1);
+ else if (vcpu->cpu != -1 && vcpu->cpu != cpu) {
+ queue_work_on(vcpu->cpu, wbinvd_wq,
+ &per_cpu(wbinvd_work, vcpu->cpu));
+ flush_workqueue(wbinvd_wq);
+ }
}
kvm_x86_ops->vcpu_load(vcpu, cpu);
@@ -3672,12 +3677,16 @@ int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
{
+ int cpu;
+
if (!need_emulate_wbinvd(vcpu))
return X86EMUL_CONTINUE;
if (kvm_x86_ops->has_wbinvd_exit()) {
- smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
- wbinvd_ipi, NULL, 1);
+ for_each_cpu(cpu, vcpu->arch.wbinvd_dirty_mask)
+ queue_work_on(cpu, wbinvd_wq,
+ &per_cpu(wbinvd_work, cpu));
+ flush_workqueue(wbinvd_wq);
cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
}
wbinvd();
@@ -4179,7 +4188,7 @@ EXPORT_SYMBOL_GPL(kvm_after_handle_nmi);
int kvm_arch_init(void *opaque)
{
- int r;
+ int r, cpu;
struct kvm_x86_ops *ops = (struct kvm_x86_ops *)opaque;
if (kvm_x86_ops) {
@@ -4218,6 +4227,16 @@ int kvm_arch_init(void *opaque)
if (cpu_has_xsave)
host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
+ for_each_possible_cpu(cpu) {
+ INIT_WORK(&per_cpu(wbinvd_work, cpu), wbinvd_do_work);
+ }
+
+ wbinvd_wq = create_workqueue("kvm_wbinvd");
+ if (!wbinvd_wq) {
+ r = -ENOMEM;
+ goto out;
+ }
+
return 0;
out:
@@ -4226,6 +4245,8 @@ out:
void kvm_arch_exit(void)
{
+ destroy_workqueue(wbinvd_wq);
+
perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
--
1.7.0.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices
2010-06-30 4:25 [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Sheng Yang
2010-06-30 4:25 ` [PATCH v6 2/2] KVM: Using workqueue for WBINVD Sheng Yang
@ 2010-06-30 16:34 ` Marcelo Tosatti
1 sibling, 0 replies; 4+ messages in thread
From: Marcelo Tosatti @ 2010-06-30 16:34 UTC (permalink / raw)
To: Sheng Yang; +Cc: Avi Kivity, Jan Kiszka, Joerg Roedel, kvm, Yaozu (Eddie) Dong
On Wed, Jun 30, 2010 at 12:25:15PM +0800, Sheng Yang wrote:
> Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly
> WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or
> CLFLUSH, we need to maintain data consistency either by:
> 1: flushing cache (wbinvd) when the guest is scheduled out if there is no
> wbinvd exit, or
> 2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits.
>
> Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
> Signed-off-by: Sheng Yang <sheng@linux.intel.com>
> ---
> arch/x86/include/asm/kvm_host.h | 6 +++++
> arch/x86/kvm/emulate.c | 5 +++-
> arch/x86/kvm/svm.c | 7 ++++++
> arch/x86/kvm/vmx.c | 10 ++++++++-
> arch/x86/kvm/x86.c | 41 +++++++++++++++++++++++++++++++++++++++
> 5 files changed, 67 insertions(+), 2 deletions(-)
Applied, thanks.
.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v6 2/2] KVM: Using workqueue for WBINVD
2010-06-30 4:25 ` [PATCH v6 2/2] KVM: Using workqueue for WBINVD Sheng Yang
@ 2010-06-30 16:41 ` Marcelo Tosatti
0 siblings, 0 replies; 4+ messages in thread
From: Marcelo Tosatti @ 2010-06-30 16:41 UTC (permalink / raw)
To: Sheng Yang; +Cc: Avi Kivity, Jan Kiszka, Joerg Roedel, kvm
On Wed, Jun 30, 2010 at 12:25:16PM +0800, Sheng Yang wrote:
> It would buy us the ability to schedule compared to smp_call_function().
>
> Signed-off-by: Sheng Yang <sheng@linux.intel.com>
> ---
>
> But I am not sure if it worth the complexity. Anyway WBINVD itself can't be
> interrupted, so the benefit should come to the caller cpu I think. And that
> would extended the waiting time for the caller cpu, for we still need to wait
> other cpus to complete their works.
Alright, can be done later in case it shows to be necessary.
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/x86.c | 35 ++++++++++++++++++++++++++++-------
> 2 files changed, 29 insertions(+), 7 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 2bda624..6e0b793 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -16,6 +16,7 @@
> #include <linux/mmu_notifier.h>
> #include <linux/tracepoint.h>
> #include <linux/cpumask.h>
> +#include <linux/workqueue.h>
>
> #include <linux/kvm.h>
> #include <linux/kvm_para.h>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index eea75f5..13f7c88 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -153,6 +153,9 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
>
> u64 __read_mostly host_xcr0;
>
> +static struct workqueue_struct *wbinvd_wq;
> +static DEFINE_PER_CPU(struct work_struct, wbinvd_work);
> +
> static inline u32 bit(int bitno)
> {
> return 1 << (bitno & 31);
> @@ -1783,7 +1786,7 @@ out:
> return r;
> }
>
> -static void wbinvd_ipi(void *garbage)
> +static void wbinvd_do_work(struct work_struct *work)
> {
> wbinvd();
> }
> @@ -1800,9 +1803,11 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> if (need_emulate_wbinvd(vcpu)) {
> if (kvm_x86_ops->has_wbinvd_exit())
> cpumask_set_cpu(cpu, vcpu->arch.wbinvd_dirty_mask);
> - else if (vcpu->cpu != -1 && vcpu->cpu != cpu)
> - smp_call_function_single(vcpu->cpu,
> - wbinvd_ipi, NULL, 1);
> + else if (vcpu->cpu != -1 && vcpu->cpu != cpu) {
> + queue_work_on(vcpu->cpu, wbinvd_wq,
> + &per_cpu(wbinvd_work, vcpu->cpu));
> + flush_workqueue(wbinvd_wq);
> + }
Can't schedule here since preemption must be disabled during vcpu_load.
> }
>
> kvm_x86_ops->vcpu_load(vcpu, cpu);
> @@ -3672,12 +3677,16 @@ int emulate_invlpg(struct kvm_vcpu *vcpu, gva_t address)
>
> int kvm_emulate_wbinvd(struct kvm_vcpu *vcpu)
> {
> + int cpu;
> +
> if (!need_emulate_wbinvd(vcpu))
> return X86EMUL_CONTINUE;
>
> if (kvm_x86_ops->has_wbinvd_exit()) {
> - smp_call_function_many(vcpu->arch.wbinvd_dirty_mask,
> - wbinvd_ipi, NULL, 1);
> + for_each_cpu(cpu, vcpu->arch.wbinvd_dirty_mask)
> + queue_work_on(cpu, wbinvd_wq,
> + &per_cpu(wbinvd_work, cpu));
> + flush_workqueue(wbinvd_wq);
> cpumask_clear(vcpu->arch.wbinvd_dirty_mask);
> }
> wbinvd();
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2010-06-30 17:03 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-06-30 4:25 [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Sheng Yang
2010-06-30 4:25 ` [PATCH v6 2/2] KVM: Using workqueue for WBINVD Sheng Yang
2010-06-30 16:41 ` Marcelo Tosatti
2010-06-30 16:34 ` [PATCH v6 1/2] KVM: VMX: Execute WBINVD to keep data consistency with assigned devices Marcelo Tosatti
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