Patchwork [2/2] Qemu co-operation with kvm tsc deadline timer

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Submitter Liu, Jinsong
Date Sept. 13, 2011, 2:38 p.m.
Message ID <BC00F5384FCFC9499AF06F92E8B78A9E254455B6C7@shsmsx502.ccr.corp.intel.com>
Download mbox | patch
Permalink /patch/114504/
State New
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Liu, Jinsong - Sept. 13, 2011, 2:38 p.m.
From c1b502d6548fcc41592cd90acc82109ee949df75 Mon Sep 17 00:00:00 2001
From: Liu, Jinsong <jinsong.liu@intel.com>
Date: Tue, 13 Sep 2011 22:05:30 +0800
Subject: [PATCH] Qemu co-operation with kvm tsc deadline timer

KVM add emulation of lapic tsc deadline timer for guest.
This patch is co-operation work at qemu side.

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
---
 target-i386/cpu.h |    2 ++
 target-i386/kvm.c |   14 ++++++++++++++
 2 files changed, 16 insertions(+), 0 deletions(-)
Jan Kiszka - Sept. 13, 2011, 3:12 p.m.
On 2011-09-13 16:38, Liu, Jinsong wrote:
> From c1b502d6548fcc41592cd90acc82109ee949df75 Mon Sep 17 00:00:00 2001
> From: Liu, Jinsong <jinsong.liu@intel.com>
> Date: Tue, 13 Sep 2011 22:05:30 +0800
> Subject: [PATCH] Qemu co-operation with kvm tsc deadline timer
> 
> KVM add emulation of lapic tsc deadline timer for guest.
> This patch is co-operation work at qemu side.
> 
> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>
> ---
>  target-i386/cpu.h |    2 ++
>  target-i386/kvm.c |   14 ++++++++++++++
>  2 files changed, 16 insertions(+), 0 deletions(-)
> 
> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> index 935d08a..62ff73c 100644
> --- a/target-i386/cpu.h
> +++ b/target-i386/cpu.h
> @@ -283,6 +283,7 @@
>  #define MSR_IA32_APICBASE_BSP           (1<<8)
>  #define MSR_IA32_APICBASE_ENABLE        (1<<11)
>  #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
> +#define MSR_IA32_TSCDEADLINE            0x6e0
>  
>  #define MSR_MTRRcap			0xfe
>  #define MSR_MTRRcap_VCNT		8
> @@ -687,6 +688,7 @@ typedef struct CPUX86State {
>      uint64_t async_pf_en_msr;
>  
>      uint64_t tsc;
> +    uint64_t tsc_deadline;

This field has to be saved/restored for snapshots/migrations.

Frankly, I've no clue right now if substates are in vogue again (they
had problems in their binary format) or if you can simply add a
versioned top-level field and bump the CPUState version number.

>  
>      uint64_t mcg_status;
>  
> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
> index aa843f0..206fcad 100644
> --- a/target-i386/kvm.c
> +++ b/target-i386/kvm.c
> @@ -59,6 +59,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
>  
>  static bool has_msr_star;
>  static bool has_msr_hsave_pa;
> +static bool has_msr_tsc_deadline;
>  static bool has_msr_async_pf_en;
>  static int lm_capable_kernel;
>  
> @@ -571,6 +572,10 @@ static int kvm_get_supported_msrs(KVMState *s)
>                      has_msr_hsave_pa = true;
>                      continue;
>                  }
> +                if (kvm_msr_list->indices[i] == MSR_IA32_TSCDEADLINE) {
> +                    has_msr_tsc_deadline = true;
> +                    continue;
> +                }
>              }
>          }
>  
> @@ -899,6 +904,9 @@ static int kvm_put_msrs(CPUState *env, int level)
>      if (has_msr_hsave_pa) {
>          kvm_msr_entry_set(&msrs[n++], MSR_VM_HSAVE_PA, env->vm_hsave);
>      }
> +    if (has_msr_tsc_deadline) {
> +        kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSCDEADLINE, env->tsc_deadline);
> +    }
>  #ifdef TARGET_X86_64
>      if (lm_capable_kernel) {
>          kvm_msr_entry_set(&msrs[n++], MSR_CSTAR, env->cstar);
> @@ -1145,6 +1153,9 @@ static int kvm_get_msrs(CPUState *env)
>      if (has_msr_hsave_pa) {
>          msrs[n++].index = MSR_VM_HSAVE_PA;
>      }
> +    if (has_msr_tsc_deadline) {
> +        msrs[n++].index = MSR_IA32_TSCDEADLINE;
> +    }
>  
>      if (!env->tsc_valid) {
>          msrs[n++].index = MSR_IA32_TSC;
> @@ -1213,6 +1224,9 @@ static int kvm_get_msrs(CPUState *env)
>          case MSR_IA32_TSC:
>              env->tsc = msrs[i].data;
>              break;
> +        case MSR_IA32_TSCDEADLINE:
> +            env->tsc_deadline = msrs[i].data;
> +            break;
>          case MSR_VM_HSAVE_PA:
>              env->vm_hsave = msrs[i].data;
>              break;

Just to double check: This feature is exposed to the guest when A) the
host CPU supports it and B) QEMU passed down guest CPU specifications
(cpuid data) that allow it as well?

Jan
Liu, Jinsong - Sept. 14, 2011, 2:51 a.m.
Jan Kiszka wrote:
> On 2011-09-13 16:38, Liu, Jinsong wrote:
>> From c1b502d6548fcc41592cd90acc82109ee949df75 Mon Sep 17 00:00:00
>> 2001 
>> From: Liu, Jinsong <jinsong.liu@intel.com>
>> Date: Tue, 13 Sep 2011 22:05:30 +0800
>> Subject: [PATCH] Qemu co-operation with kvm tsc deadline timer
>> 
>> KVM add emulation of lapic tsc deadline timer for guest.
>> This patch is co-operation work at qemu side.
>> 
>> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> ---
>>  target-i386/cpu.h |    2 ++
>>  target-i386/kvm.c |   14 ++++++++++++++
>>  2 files changed, 16 insertions(+), 0 deletions(-)
>> 
>> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
>> index 935d08a..62ff73c 100644
>> --- a/target-i386/cpu.h
>> +++ b/target-i386/cpu.h
>> @@ -283,6 +283,7 @@
>>  #define MSR_IA32_APICBASE_BSP           (1<<8)
>>  #define MSR_IA32_APICBASE_ENABLE        (1<<11)
>>  #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
>> +#define MSR_IA32_TSCDEADLINE            0x6e0
>> 
>>  #define MSR_MTRRcap			0xfe
>>  #define MSR_MTRRcap_VCNT		8
>> @@ -687,6 +688,7 @@ typedef struct CPUX86State {
>>      uint64_t async_pf_en_msr;
>> 
>>      uint64_t tsc;
>> +    uint64_t tsc_deadline;
> 
> This field has to be saved/restored for snapshots/migrations.
> 
> Frankly, I've no clue right now if substates are in vogue again (they
> had problems in their binary format) or if you can simply add a
> versioned top-level field and bump the CPUState version number.
> 

Yes, it would be saved/restored. After migration, tsc_deadline would be set to MSR_IA32_TSCDEADLINE to trigger tsc timer interrupt.

>> 
>>      uint64_t mcg_status;
>> 
>> diff --git a/target-i386/kvm.c b/target-i386/kvm.c
>> index aa843f0..206fcad 100644
>> --- a/target-i386/kvm.c
>> +++ b/target-i386/kvm.c
>> @@ -59,6 +59,7 @@ const KVMCapabilityInfo
>> kvm_arch_required_capabilities[] = { 
>> 
>>  static bool has_msr_star;
>>  static bool has_msr_hsave_pa;
>> +static bool has_msr_tsc_deadline;
>>  static bool has_msr_async_pf_en;
>>  static int lm_capable_kernel;
>> 
>> @@ -571,6 +572,10 @@ static int kvm_get_supported_msrs(KVMState *s)
>>                      has_msr_hsave_pa = true;
>>                      continue;
>>                  }
>> +                if (kvm_msr_list->indices[i] ==
>> MSR_IA32_TSCDEADLINE) { +                    has_msr_tsc_deadline =
>> true; +                    continue;
>> +                }
>>              }
>>          }
>> 
>> @@ -899,6 +904,9 @@ static int kvm_put_msrs(CPUState *env, int
>>          level)      if (has_msr_hsave_pa) {
>> kvm_msr_entry_set(&msrs[n++], MSR_VM_HSAVE_PA, env->vm_hsave);     
>> } +    if (has_msr_tsc_deadline) { +       
>>  kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSCDEADLINE,
>>      env->tsc_deadline); +    } #ifdef TARGET_X86_64 if
>>          (lm_capable_kernel) { kvm_msr_entry_set(&msrs[n++],
>> MSR_CSTAR, env->cstar); @@ -1145,6 +1153,9 @@ static int
>>          kvm_get_msrs(CPUState *env)      if (has_msr_hsave_pa) {
>>      msrs[n++].index = MSR_VM_HSAVE_PA; }
>> +    if (has_msr_tsc_deadline) {
>> +        msrs[n++].index = MSR_IA32_TSCDEADLINE;
>> +    }
>> 
>>      if (!env->tsc_valid) {
>>          msrs[n++].index = MSR_IA32_TSC;
>> @@ -1213,6 +1224,9 @@ static int kvm_get_msrs(CPUState *env)        
>>              case MSR_IA32_TSC: env->tsc = msrs[i].data;
>>              break;
>> +        case MSR_IA32_TSCDEADLINE:
>> +            env->tsc_deadline = msrs[i].data;
>> +            break;
>>          case MSR_VM_HSAVE_PA:
>>              env->vm_hsave = msrs[i].data;
>>              break;
> 
> Just to double check: This feature is exposed to the guest when A) the
> host CPU supports it and B) QEMU passed down guest CPU specifications
> (cpuid data) that allow it as well?
> 
> Jan

Yes.

Thanks,
Jinsong
Marcelo Tosatti - Sept. 14, 2011, 11:47 a.m.
On Wed, Sep 14, 2011 at 10:51:41AM +0800, Liu, Jinsong wrote:
> Jan Kiszka wrote:
> > On 2011-09-13 16:38, Liu, Jinsong wrote:
> >> From c1b502d6548fcc41592cd90acc82109ee949df75 Mon Sep 17 00:00:00
> >> 2001 
> >> From: Liu, Jinsong <jinsong.liu@intel.com>
> >> Date: Tue, 13 Sep 2011 22:05:30 +0800
> >> Subject: [PATCH] Qemu co-operation with kvm tsc deadline timer
> >> 
> >> KVM add emulation of lapic tsc deadline timer for guest.
> >> This patch is co-operation work at qemu side.
> >> 
> >> Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> ---
> >>  target-i386/cpu.h |    2 ++
> >>  target-i386/kvm.c |   14 ++++++++++++++
> >>  2 files changed, 16 insertions(+), 0 deletions(-)
> >> 
> >> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> >> index 935d08a..62ff73c 100644
> >> --- a/target-i386/cpu.h
> >> +++ b/target-i386/cpu.h
> >> @@ -283,6 +283,7 @@
> >>  #define MSR_IA32_APICBASE_BSP           (1<<8)
> >>  #define MSR_IA32_APICBASE_ENABLE        (1<<11)
> >>  #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
> >> +#define MSR_IA32_TSCDEADLINE            0x6e0
> >> 
> >>  #define MSR_MTRRcap			0xfe
> >>  #define MSR_MTRRcap_VCNT		8
> >> @@ -687,6 +688,7 @@ typedef struct CPUX86State {
> >>      uint64_t async_pf_en_msr;
> >> 
> >>      uint64_t tsc;
> >> +    uint64_t tsc_deadline;
> > 
> > This field has to be saved/restored for snapshots/migrations.
> > 
> > Frankly, I've no clue right now if substates are in vogue again (they
> > had problems in their binary format) or if you can simply add a
> > versioned top-level field and bump the CPUState version number.
> > 
> 
> Yes, it would be saved/restored. After migration, tsc_deadline would be set to MSR_IA32_TSCDEADLINE to trigger tsc timer interrupt.

Jan means you should explicitly add this to machine.c.

Patch

diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 935d08a..62ff73c 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -283,6 +283,7 @@ 
 #define MSR_IA32_APICBASE_BSP           (1<<8)
 #define MSR_IA32_APICBASE_ENABLE        (1<<11)
 #define MSR_IA32_APICBASE_BASE          (0xfffff<<12)
+#define MSR_IA32_TSCDEADLINE            0x6e0
 
 #define MSR_MTRRcap			0xfe
 #define MSR_MTRRcap_VCNT		8
@@ -687,6 +688,7 @@  typedef struct CPUX86State {
     uint64_t async_pf_en_msr;
 
     uint64_t tsc;
+    uint64_t tsc_deadline;
 
     uint64_t mcg_status;
 
diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index aa843f0..206fcad 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -59,6 +59,7 @@  const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
 
 static bool has_msr_star;
 static bool has_msr_hsave_pa;
+static bool has_msr_tsc_deadline;
 static bool has_msr_async_pf_en;
 static int lm_capable_kernel;
 
@@ -571,6 +572,10 @@  static int kvm_get_supported_msrs(KVMState *s)
                     has_msr_hsave_pa = true;
                     continue;
                 }
+                if (kvm_msr_list->indices[i] == MSR_IA32_TSCDEADLINE) {
+                    has_msr_tsc_deadline = true;
+                    continue;
+                }
             }
         }
 
@@ -899,6 +904,9 @@  static int kvm_put_msrs(CPUState *env, int level)
     if (has_msr_hsave_pa) {
         kvm_msr_entry_set(&msrs[n++], MSR_VM_HSAVE_PA, env->vm_hsave);
     }
+    if (has_msr_tsc_deadline) {
+        kvm_msr_entry_set(&msrs[n++], MSR_IA32_TSCDEADLINE, env->tsc_deadline);
+    }
 #ifdef TARGET_X86_64
     if (lm_capable_kernel) {
         kvm_msr_entry_set(&msrs[n++], MSR_CSTAR, env->cstar);
@@ -1145,6 +1153,9 @@  static int kvm_get_msrs(CPUState *env)
     if (has_msr_hsave_pa) {
         msrs[n++].index = MSR_VM_HSAVE_PA;
     }
+    if (has_msr_tsc_deadline) {
+        msrs[n++].index = MSR_IA32_TSCDEADLINE;
+    }
 
     if (!env->tsc_valid) {
         msrs[n++].index = MSR_IA32_TSC;
@@ -1213,6 +1224,9 @@  static int kvm_get_msrs(CPUState *env)
         case MSR_IA32_TSC:
             env->tsc = msrs[i].data;
             break;
+        case MSR_IA32_TSCDEADLINE:
+            env->tsc_deadline = msrs[i].data;
+            break;
         case MSR_VM_HSAVE_PA:
             env->vm_hsave = msrs[i].data;
             break;