[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-ppc] [QEMU-PPC] [PATCH V2 1/2] target/ppc: Don't require priva
From: |
David Gibson |
Subject: |
Re: [Qemu-ppc] [QEMU-PPC] [PATCH V2 1/2] target/ppc: Don't require private l1d cache on POWER8 for cap_ppc_safe_cache |
Date: |
Tue, 12 Jun 2018 21:19:17 +1000 |
User-agent: |
Mutt/1.10.0 (2018-05-17) |
On Tue, Jun 12, 2018 at 03:16:29PM +1000, Suraj Jitindar Singh wrote:
> For cap_ppc_safe_cache to be set to workaround, we require both a l1d
> cache flush instruction and private l1d cache.
>
> On POWER8 don't require private l1d cache. This means a guest on a
> POWER8 machine can make use of the cache flush workarounds.
>
> Signed-off-by: Suraj Jitindar Singh <address@hidden>
Applied to ppc-for-3.0, thanks.
>
> ---
>
> V1 -> V2:
> - Use mfpvr() to detect host type
>
> ---
> target/ppc/kvm.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
> index 2c0c34e125..7fe9d0126b 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -2412,11 +2412,28 @@ bool kvmppc_has_cap_mmu_hash_v3(void)
> return cap_mmu_hash_v3;
> }
>
> +static bool kvmppc_power8_host(void)
> +{
> + bool ret = false;
> +#ifdef TARGET_PPC64
> + {
> + uint32_t base_pvr = CPU_POWERPC_POWER_SERVER_MASK & mfpvr();
> + ret = (base_pvr == CPU_POWERPC_POWER8E_BASE) ||
> + (base_pvr == CPU_POWERPC_POWER8NVL_BASE) ||
> + (base_pvr == CPU_POWERPC_POWER8_BASE);
> + }
> +#endif /* TARGET_PPC64 */
> + return ret;
> +}
> +
> static int parse_cap_ppc_safe_cache(struct kvm_ppc_cpu_char c)
> {
> + bool l1d_thread_priv_req = !kvmppc_power8_host();
> +
> if (~c.behaviour & c.behaviour_mask & H_CPU_BEHAV_L1D_FLUSH_PR) {
> return 2;
> - } else if ((c.character & c.character_mask & H_CPU_CHAR_L1D_THREAD_PRIV)
> &&
> + } else if ((!l1d_thread_priv_req ||
> + c.character & c.character_mask & H_CPU_CHAR_L1D_THREAD_PRIV)
> &&
> (c.character & c.character_mask
> & (H_CPU_CHAR_L1D_FLUSH_ORI30 |
> H_CPU_CHAR_L1D_FLUSH_TRIG2))) {
> return 1;
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
signature.asc
Description: PGP signature