Re: [Qemu-devel] [PATCH 2/2] pseries: Implement hcall-bulk hypervisor interface

[Alexander Graf]

On 11.08.2011, at 04:36, David Gibson wrote:

> This patch adds support for the H_REMOVE_BULK hypercall on the pseries
> machine.  Strictly speaking this isn't necessarym since the kernel will
> only attempt to use this if hcall-bulk is advertised in the device tree,
> which previously it was not.
> 
> Adding this support may give a marginal performance increase, but more
> importantly it reduces the differences between the emulated machine and
> an existing PowerVM or kvm system, both of which already implement
> hcall-bulk.
> 
> Signed-off-by: David Gibson <address@hidden>
> ---
> hw/spapr.c       |    2 +-
> hw/spapr_hcall.c |  122 ++++++++++++++++++++++++++++++++++++++++++++++++-----
> 2 files changed, 111 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/spapr.c b/hw/spapr.c
> index 3f4433c..0db1051 100644
> --- a/hw/spapr.c
> +++ b/hw/spapr.c
> @@ -72,7 +72,7 @@ static void *spapr_create_fdt_skel(const char *cpu_model,
>     uint32_t end_prop = cpu_to_be32(initrd_base + initrd_size);
>     uint32_t pft_size_prop[] = {0, cpu_to_be32(hash_shift)};
>     char hypertas_prop[] = 
> "hcall-pft\0hcall-term\0hcall-dabr\0hcall-interrupt"
> -        "\0hcall-tce\0hcall-vio\0hcall-splpar";
> +        "\0hcall-tce\0hcall-vio\0hcall-splpar\0hcall-bulk";
>     uint32_t interrupt_server_ranges_prop[] = {0, cpu_to_be32(smp_cpus)};
>     int i;
>     char *modelname;
> diff --git a/hw/spapr_hcall.c b/hw/spapr_hcall.c
> index 0c61c10..9ac42ee 100644
> --- a/hw/spapr_hcall.c
> +++ b/hw/spapr_hcall.c
> @@ -174,20 +174,25 @@ static target_ulong h_enter(CPUState *env, 
> sPAPREnvironment *spapr,
>     return H_SUCCESS;
> }
> 
> -static target_ulong h_remove(CPUState *env, sPAPREnvironment *spapr,
> -                             target_ulong opcode, target_ulong *args)
> +enum {
> +    REMOVE_SUCCESS = 0,
> +    REMOVE_NOT_FOUND = 1,
> +    REMOVE_PARM = 2,
> +    REMOVE_HW = 3,
> +};
> +
> +static target_ulong remove_hpte(CPUState *env, target_ulong ptex, 
> target_ulong avpn,
> +                                target_ulong flags,
> +                                target_ulong *vp, target_ulong *rp)
> {
> -    target_ulong flags = args[0];
> -    target_ulong pte_index = args[1];
> -    target_ulong avpn = args[2];
>     uint8_t *hpte;
>     target_ulong v, r, rb;
> 
> -    if ((pte_index * HASH_PTE_SIZE_64) & ~env->htab_mask) {
> -        return H_PARAMETER;
> +    if ((ptex * HASH_PTE_SIZE_64) & ~env->htab_mask) {
> +        return REMOVE_PARM;
>     }
> 
> -    hpte = env->external_htab + (pte_index * HASH_PTE_SIZE_64);
> +    hpte = env->external_htab + (ptex * HASH_PTE_SIZE_64);
>     while (!lock_hpte(hpte, HPTE_V_HVLOCK)) {
>         /* We have no real concurrency in qemu soft-emulation, so we
>          * will never actually have a contested lock */
> @@ -202,14 +207,104 @@ static target_ulong h_remove(CPUState *env, 
> sPAPREnvironment *spapr,
>         ((flags & H_ANDCOND) && (v & avpn) != 0)) {
>         stq_p(hpte, v & ~HPTE_V_HVLOCK);
>         assert(!(ldq_p(hpte) & HPTE_V_HVLOCK));
> -        return H_NOT_FOUND;
> +        return REMOVE_NOT_FOUND;
>     }
> -    args[0] = v & ~HPTE_V_HVLOCK;
> -    args[1] = r;
> +    *vp = v & ~HPTE_V_HVLOCK;
> +    *rp = r;
>     stq_p(hpte, 0);
> -    rb = compute_tlbie_rb(v, r, pte_index);
> +    rb = compute_tlbie_rb(v, r, ptex);
>     ppc_tlb_invalidate_one(env, rb);
>     assert(!(ldq_p(hpte) & HPTE_V_HVLOCK));
> +    return REMOVE_SUCCESS;
> +}
> +
> +static target_ulong h_remove(CPUState *env, sPAPREnvironment *spapr,
> +                             target_ulong opcode, target_ulong *args)
> +{
> +    target_ulong flags = args[0];
> +    target_ulong pte_index = args[1];
> +    target_ulong avpn = args[2];
> +    int ret;
> +
> +    ret = remove_hpte(env, pte_index, avpn, flags,
> +                      &args[0], &args[1]);
> +
> +    switch (ret) {
> +    case REMOVE_SUCCESS:
> +        return H_SUCCESS;
> +        
> +    case REMOVE_NOT_FOUND:
> +        return H_NOT_FOUND;
> +
> +    case REMOVE_PARM:
> +        return H_PARAMETER;
> +
> +    case REMOVE_HW:
> +        return H_HARDWARE;
> +    }
> +
> +    assert(0);
> +}
> +
> +#define H_BULK_REMOVE_TYPE             0xc000000000000000ULL
> +#define   H_BULK_REMOVE_REQUEST        0x4000000000000000ULL
> +#define   H_BULK_REMOVE_RESPONSE       0x8000000000000000ULL
> +#define   H_BULK_REMOVE_END            0xc000000000000000ULL
> +#define H_BULK_REMOVE_CODE             0x3000000000000000ULL
> +#define   H_BULK_REMOVE_SUCCESS        0x0000000000000000ULL
> +#define   H_BULK_REMOVE_NOT_FOUND      0x1000000000000000ULL
> +#define   H_BULK_REMOVE_PARM           0x2000000000000000ULL
> +#define   H_BULK_REMOVE_HW             0x3000000000000000ULL
> +#define H_BULK_REMOVE_RC               0x0c00000000000000ULL
> +#define H_BULK_REMOVE_FLAGS            0x0300000000000000ULL
> +#define   H_BULK_REMOVE_ABSOLUTE       0x0000000000000000ULL
> +#define   H_BULK_REMOVE_ANDCOND        0x0100000000000000ULL
> +#define   H_BULK_REMOVE_AVPN           0x0200000000000000ULL
> +#define H_BULK_REMOVE_PTEX             0x00ffffffffffffffULL

indenting looks broken.

> +
> +static target_ulong h_bulk_remove(CPUState *env, sPAPREnvironment *spapr,
> +                                  target_ulong opcode, target_ulong *args)
> +{
> +    int i;
> +
> +    for (i = 0; i < 4; i++) {
> +        target_ulong *tsh = &args[i*2];
> +        target_ulong tsl = args[i*2 + 1];

Mind to replace all those magic numbers by something more verbose?


Alex