Re: [Qemu-devel] [PATCHv2] qemu: enable PV EOI for qemu 1.3

["Andreas Färber" <afaerber@suse.de>]

Am 18.10.2012 00:15, schrieb Michael S. Tsirkin:
> Enable KVM PV EOI by default. You can still disable it with
> -kvm_pv_eoi cpu flag. To avoid breaking cross-version migration,
> enable only for qemu 1.3 (or in the future, newer) machine type.
> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> 
> Changes from v1:
>     Address comments by Eduardo:
>         use include instead of duplicate definition
>         reduce ifdef spagetti in code using features mask
>         rename init from _pv_eoi to _1_3 to enable adding
>         more stuff in this version
> 
>  hw/pc_piix.c      | 15 ++++++++++++++-
>  target-i386/cpu.c | 33 ++++++++++++++++++++-------------
>  target-i386/cpu.h |  2 ++
>  3 files changed, 36 insertions(+), 14 deletions(-)
> 
> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
> index 82364ab..607de77 100644
> --- a/hw/pc_piix.c
> +++ b/hw/pc_piix.c
> @@ -43,6 +43,7 @@
>  #include "xen.h"
>  #include "memory.h"
>  #include "exec-memory.h"
> +#include "cpu.h"
>  #ifdef CONFIG_XEN
>  #  include <xen/hvm/hvm_info_table.h>
>  #endif
> @@ -301,6 +302,18 @@ static void pc_init_pci(ram_addr_t ram_size,
>               initrd_filename, cpu_model, 1, 1);
>  }
>  
> +static void pc_init_pci_1_3(ram_addr_t ram_size,
> +                               const char *boot_device,
> +                               const char *kernel_filename,
> +                               const char *kernel_cmdline,
> +                               const char *initrd_filename,
> +                               const char *cpu_model)

Indentation was not adapted to name change?

> +{
> +    enable_kvm_pv_eoi();
> +    pc_init_pci(ram_size, boot_device, kernel_filename,
> +		kernel_cmdline, initrd_filename, cpu_model);

There's two tabs here.

Thought you wanted to s/pc_init_pci/pc_init_pci_1_2/g and name this
pc_init_pci()? Are you expecting there to be a pc_init_pci_1_4()?

> +}
> +
>  static void pc_init_pci_no_kvmclock(ram_addr_t ram_size,
>                                      const char *boot_device,
>                                      const char *kernel_filename,
> @@ -353,7 +366,7 @@ static QEMUMachine pc_machine_v1_3 = {
>      .name = "pc-1.3",
>      .alias = "pc",
>      .desc = "Standard PC",
> -    .init = pc_init_pci,
> +    .init = pc_init_pci_1_3,
>      .max_cpus = 255,
>      .is_default = 1,
>  };
> diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> index f3708e6..5f316b3 100644
> --- a/target-i386/cpu.c
> +++ b/target-i386/cpu.c
> @@ -124,6 +124,20 @@ typedef struct model_features_t {
>  int check_cpuid = 0;
>  int enforce_cpuid = 0;
>  
> +#if defined(CONFIG_KVM)
> +static uint32_t kvm_default_features = (1 << KVM_FEATURE_CLOCKSOURCE) |
> +        (1 << KVM_FEATURE_NOP_IO_DELAY) | 
> +        (1 << KVM_FEATURE_MMU_OP) |
> +        (1 << KVM_FEATURE_CLOCKSOURCE2) |
> +        (1 << KVM_FEATURE_ASYNC_PF) | 
> +        (1 << KVM_FEATURE_STEAL_TIME) |
> +        (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
> +static const uint32_t kvm_pv_eoi_features = (0x1 << KVM_FEATURE_PV_EOI);
> +#else
> +static uint32_t kvm_default_features = 0;
> +static const uint32_t kvm_pv_eoi_features = 0;
> +#endif
> +
>  void host_cpuid(uint32_t function, uint32_t count,
>                  uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx)
>  {
> @@ -1107,7 +1121,7 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
>      /* Features to be added*/
>      uint32_t plus_features = 0, plus_ext_features = 0;
>      uint32_t plus_ext2_features = 0, plus_ext3_features = 0;
> -    uint32_t plus_kvm_features = 0, plus_svm_features = 0;
> +    uint32_t plus_kvm_features = kvm_default_features, plus_svm_features = 0;
>      uint32_t plus_7_0_ebx_features = 0;
>      /* Features to be removed */
>      uint32_t minus_features = 0, minus_ext_features = 0;
> @@ -1127,18 +1141,6 @@ static int cpu_x86_find_by_name(x86_def_t *x86_cpu_def, const char *cpu_model)
>          memcpy(x86_cpu_def, def, sizeof(*def));
>      }
>  
> -#if defined(CONFIG_KVM)
> -    plus_kvm_features = (1 << KVM_FEATURE_CLOCKSOURCE) |
> -        (1 << KVM_FEATURE_NOP_IO_DELAY) | 
> -        (1 << KVM_FEATURE_MMU_OP) |
> -        (1 << KVM_FEATURE_CLOCKSOURCE2) |
> -        (1 << KVM_FEATURE_ASYNC_PF) | 
> -        (1 << KVM_FEATURE_STEAL_TIME) |
> -        (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT);
> -#else
> -    plus_kvm_features = 0;
> -#endif
> -
>      add_flagname_to_bitmaps("hypervisor", &plus_features,
>              &plus_ext_features, &plus_ext2_features, &plus_ext3_features,
>              &plus_kvm_features, &plus_svm_features,  &plus_7_0_ebx_features);
> @@ -1953,3 +1955,8 @@ static void x86_cpu_register_types(void)
>  }
>  
>  type_init(x86_cpu_register_types)
> +
> +void enable_kvm_pv_eoi(void)
> +{
> +       kvm_default_features |= kvm_pv_eoi_features;
> +}

Indentation is off (7 spaces).

I'd prefer to place this function below the variable definitions, so
that type_init() remains at the bottom of the file.

Otherwise I'm happy with the modified cpu.h-based interaction.
So far there's no conflicts here, so it could go through either PC
maintainer, kvm/uq or qom-cpu.

Andreas

> diff --git a/target-i386/cpu.h b/target-i386/cpu.h
> index 871c270..de33303 100644
> --- a/target-i386/cpu.h
> +++ b/target-i386/cpu.h
> @@ -1188,4 +1188,6 @@ void do_smm_enter(CPUX86State *env1);
>  
>  void cpu_report_tpr_access(CPUX86State *env, TPRAccess access);
>  
> +void enable_kvm_pv_eoi(void);
> +
>  #endif /* CPU_I386_H */


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