[Qemu-devel] [PATCH RFC 0/2] Add guest cpu entitlement reporting

[Qemu-devel] [PATCH RFC 0/2] Add guest cpu entitlement reporting

[Michael Wolf]

User can be confused by stealtime when running a guest in either a capped or
overcommitted cpu environment.  The user has concerns that they are not 
receiving their full cpu allotment when steal time shows up in the accounting 
tools.  So add a cpu entitlement.  This entitlement will be used to compute the
amount of steal time display by the accounting tools. 

Michael Wolf (2):
      The cpu entitlement value will be passed to qemu as part of the cpu 
      parameters.

      Add an ioctl to pass the entitlement information from qemu to the 
      hypervisor.
---
 cpu-defs.h                |    1 +
 cpus.c                    |    1 +
 cpus.h                    |    1 +
 kvm-all.c                 |    1 +
 linux-headers/linux/kvm.h |    2 ++
 qemu-options.hx           |    7 +++++--
 vl.c                      |   22 +++++++++++++++++++++-
 7 files changed, 32 insertions(+), 3 deletions(-)

[Qemu-devel] [PATCH RFC 1/2] Parse the cpu entitlement from the qemu commandline.

[Michael Wolf]

The cpu entitlement value will be passed to qemu as part of the cpu parameters.
Add cpu_parse to read this value from the commandline.

Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com>
---
 qemu-options.hx |    7 +++++--
 vl.c            |   23 ++++++++++++++++++++++-
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/qemu-options.hx b/qemu-options.hx
index 3c411c4..d13aa24 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -64,9 +64,12 @@ HXCOMM Deprecated by -machine
 DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
 
 DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
-    "-cpu cpu        select CPU (-cpu ? for list)\n", QEMU_ARCH_ALL)
+    "-cpu cpu[,entitlement=cpu use entitlement %]\n"
+    "select CPU (-cpu ? for list)\n"
+    "entitlement= percentage of cpu that the guest can expect to utilize\n",
+    QEMU_ARCH_ALL)
 STEXI
-@item -cpu @var{model}
+@item -cpu @var{model}[,entitlement=@var{entitlement}]
 @findex -cpu
 Select CPU model (-cpu ? for list and additional feature selection)
 ETEXI
diff --git a/vl.c b/vl.c
index 7c577fa..8f0c12a 100644
--- a/vl.c
+++ b/vl.c
@@ -205,6 +205,8 @@ CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
 int win2k_install_hack = 0;
 int usb_enabled = 0;
 int singlestep = 0;
+const char *cpu_model;
+int cpu_entitlement = 100;
 int smp_cpus = 1;
 int max_cpus = 0;
 int smp_cores = 1;
@@ -1026,6 +1028,25 @@ static void numa_add(const char *optarg)
     return;
 }
 
+static void cpu_parse(const char *optarg)
+{
+    char option[128];
+    char *endptr;
+
+    endptr = (char *) get_opt_name(option, 128, optarg, ',');
+    *endptr = '\0';
+    endptr++;
+    if (get_param_value(option, 128, "entitlement", endptr) != 0) {
+        cpu_entitlement = strtoull(option, NULL, 10);
+    }
+    /* Make sure that the entitlement is within 1 - 100 */
+    if (cpu_entitlement < 1 || cpu_entitlement > 100) {
+        fprintf(stderr, "cpu_entitlement=%d is invalid. "
+                        "Valid range is 1 - 100\n", cpu_entitlement);
+        cpu_entitlement = 100;
+    }
+}
+
 static void smp_parse(const char *optarg)
 {
     int smp, sockets = 0, threads = 0, cores = 0;
@@ -2359,7 +2380,6 @@ int main(int argc, char **argv, char **envp)
     const char *optarg;
     const char *loadvm = NULL;
     QEMUMachine *machine;
-    const char *cpu_model;
     const char *vga_model = "none";
     const char *pid_file = NULL;
     const char *incoming = NULL;
@@ -2472,6 +2492,7 @@ int main(int argc, char **argv, char **envp)
                 break;
             case QEMU_OPTION_cpu:
                 /* hw initialization will check this */
+                cpu_parse(optarg);
                 cpu_model = optarg;
                 break;
             case QEMU_OPTION_hda:

[Qemu-devel] [PATCH RFC 2/2] Add an ioctl to pass the entitlement information from qemu to the hypervisor.

[Michael Wolf]

Add KVM_SET_ENTITLEMENT ioctl to pass the entitlement to the hypervisor.

Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com>
---
 cpu-defs.h                |    1 +
 cpus.c                    |    1 +
 cpus.h                    |    1 +
 kvm-all.c                 |    1 +
 linux-headers/linux/kvm.h |    2 ++
 5 files changed, 6 insertions(+)

diff --git a/cpu-defs.h b/cpu-defs.h
index 4018b88..ae24e8e 100644
--- a/cpu-defs.h
+++ b/cpu-defs.h
@@ -200,6 +200,7 @@ typedef struct CPUWatchpoint {
     int numa_node; /* NUMA node this cpu is belonging to  */            \
     int nr_cores;  /* number of cores within this CPU package */        \
     int nr_threads;/* number of threads within this CPU */              \
+    int cpu_entitlement; /* the % of the pcpu that the vcpu receives */ \
     int running; /* Nonzero if cpu is currently running(usermode).  */  \
     int thread_id;                                                      \
     /* user data */                                                     \
diff --git a/cpus.c b/cpus.c
index e476a3c..ef8b762 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1042,6 +1042,7 @@ void qemu_init_vcpu(void *_env)
 
     env->nr_cores = smp_cores;
     env->nr_threads = smp_threads;
+    env->cpu_entitlement = cpu_entitlement;
     env->stopped = 1;
     if (kvm_enabled()) {
         qemu_kvm_start_vcpu(env);
diff --git a/cpus.h b/cpus.h
index 81bd817..704d6df 100644
--- a/cpus.h
+++ b/cpus.h
@@ -16,6 +16,7 @@ void qtest_clock_warp(int64_t dest);
 /* vl.c */
 extern int smp_cores;
 extern int smp_threads;
+extern int cpu_entitlement;
 void set_numa_modes(void);
 void set_cpu_log(const char *optarg);
 void set_cpu_log_filename(const char *optarg);
diff --git a/kvm-all.c b/kvm-all.c
index 34b02c1..dee1b9b 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -246,6 +246,7 @@ int kvm_init_vcpu(CPUArchState *env)
         s->coalesced_mmio_ring =
             (void *)env->kvm_run + s->coalesced_mmio * PAGE_SIZE;
     }
+    kvm_vm_ioctl(s, KVM_SET_ENTITLEMENT, env->cpu_entitlement);
 
     ret = kvm_arch_init_vcpu(env);
     if (ret == 0) {
diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index 5a9d4e3..46dbde5 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -901,6 +901,8 @@ struct kvm_s390_ucas_mapping {
 #define KVM_SET_ONE_REG		  _IOW(KVMIO,  0xac, struct kvm_one_reg)
 /* VM is being stopped by host */
 #define KVM_KVMCLOCK_CTRL	  _IO(KVMIO,   0xad)
+/* Set the cpu entitlement this will be used to adjust stealtime reporting */
+#define KVM_SET_ENTITLEMENT       _IOW(KVMIO, 0xae, unsigned long)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)
 #define KVM_DEV_ASSIGN_PCI_2_3		(1 << 1)

Re: [Qemu-devel] [PATCH RFC 1/2] Parse the cpu entitlement from the qemu commandline.

[Blue Swirl]

On Thu, Aug 23, 2012 at 11:15 PM, Michael Wolf <mjw@linux.vnet.ibm.com> wrote:
> The cpu entitlement value will be passed to qemu as part of the cpu parameters.
> Add cpu_parse to read this value from the commandline.
>
> Signed-off-by: Michael Wolf <mjw@linux.vnet.ibm.com>
> ---
>  qemu-options.hx |    7 +++++--
>  vl.c            |   23 ++++++++++++++++++++++-
>  2 files changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 3c411c4..d13aa24 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -64,9 +64,12 @@ HXCOMM Deprecated by -machine
>  DEF("M", HAS_ARG, QEMU_OPTION_M, "", QEMU_ARCH_ALL)
>
>  DEF("cpu", HAS_ARG, QEMU_OPTION_cpu,
> -    "-cpu cpu        select CPU (-cpu ? for list)\n", QEMU_ARCH_ALL)
> +    "-cpu cpu[,entitlement=cpu use entitlement %]\n"
> +    "select CPU (-cpu ? for list)\n"
> +    "entitlement= percentage of cpu that the guest can expect to utilize\n",
> +    QEMU_ARCH_ALL)
>  STEXI
> -@item -cpu @var{model}
> +@item -cpu @var{model}[,entitlement=@var{entitlement}]
>  @findex -cpu
>  Select CPU model (-cpu ? for list and additional feature selection)
>  ETEXI
> diff --git a/vl.c b/vl.c
> index 7c577fa..8f0c12a 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -205,6 +205,8 @@ CharDriverState *virtcon_hds[MAX_VIRTIO_CONSOLES];
>  int win2k_install_hack = 0;
>  int usb_enabled = 0;
>  int singlestep = 0;
> +const char *cpu_model;
> +int cpu_entitlement = 100;

Missing 'static' for the above. I'd merge this patch with the other
patch which uses the variable.

>  int smp_cpus = 1;
>  int max_cpus = 0;
>  int smp_cores = 1;
> @@ -1026,6 +1028,25 @@ static void numa_add(const char *optarg)
>      return;
>  }
>
> +static void cpu_parse(const char *optarg)
> +{
> +    char option[128];
> +    char *endptr;
> +
> +    endptr = (char *) get_opt_name(option, 128, optarg, ',');
> +    *endptr = '\0';
> +    endptr++;
> +    if (get_param_value(option, 128, "entitlement", endptr) != 0) {
> +        cpu_entitlement = strtoull(option, NULL, 10);

strtoul() should be enough.

> +    }
> +    /* Make sure that the entitlement is within 1 - 100 */
> +    if (cpu_entitlement < 1 || cpu_entitlement > 100) {
> +        fprintf(stderr, "cpu_entitlement=%d is invalid. "
> +                        "Valid range is 1 - 100\n", cpu_entitlement);

Exit or tell user that value of 100 is actually used.

> +        cpu_entitlement = 100;
> +    }

This block belongs inside the previous 'if' block, it's useless to
check the value if the option hasn't been used.

> +}
> +
>  static void smp_parse(const char *optarg)
>  {
>      int smp, sockets = 0, threads = 0, cores = 0;
> @@ -2359,7 +2380,6 @@ int main(int argc, char **argv, char **envp)
>      const char *optarg;
>      const char *loadvm = NULL;
>      QEMUMachine *machine;
> -    const char *cpu_model;
>      const char *vga_model = "none";
>      const char *pid_file = NULL;
>      const char *incoming = NULL;
> @@ -2472,6 +2492,7 @@ int main(int argc, char **argv, char **envp)
>                  break;
>              case QEMU_OPTION_cpu:
>                  /* hw initialization will check this */
> +                cpu_parse(optarg);
>                  cpu_model = optarg;
>                  break;
>              case QEMU_OPTION_hda:
>
>