Re: [PATCH v1 22/22] intel_iommu: modify x-scalable-mode to be string option

Peter Xu
2020-03-24T18:39:30Z

On Sun, Mar 22, 2020 at 05:36:19AM -0700, Liu Yi L wrote:
> Intel VT-d 3.0 introduces scalable mode, and it has a bunch of capabilities
> related to scalable mode translation, thus there are multiple combinations.
> While this vIOMMU implementation wants simplify it for user by providing
> typical combinations. User could config it by "x-scalable-mode" option. The
> usage is as below:
>
> "-device intel-iommu,x-scalable-mode=["legacy"|"modern"|"off"]"
>
> - "legacy": gives support for SL page table
> - "modern": gives support for FL page table, pasid, virtual command
> - "off": no scalable mode support
> - if not configured, means no scalable mode support, if not proper
> configured, will throw error
>
> Note: this patch is supposed to be merged when the whole vSVA patch series
> were merged.
>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Yi Sun <yi.y.sun@linux.intel.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
> ---
> hw/i386/intel_iommu.c | 29 +++++++++++++++++++++++++++--
> hw/i386/intel_iommu_internal.h | 4 ++++
> include/hw/i386/intel_iommu.h | 2 ++
> 3 files changed, 33 insertions(+), 2 deletions(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 72cd739..ea1f5c4 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -4171,7 +4171,7 @@ static Property vtd_properties[] = {
> DEFINE_PROP_UINT8("aw-bits", IntelIOMMUState, aw_bits,
> VTD_HOST_ADDRESS_WIDTH),
> DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE),
> - DEFINE_PROP_BOOL("x-scalable-mode", IntelIOMMUState, scalable_mode, FALSE),
> + DEFINE_PROP_STRING("x-scalable-mode", IntelIOMMUState, scalable_mode_str),
> DEFINE_PROP_BOOL("dma-drain", IntelIOMMUState, dma_drain, true),
> DEFINE_PROP_END_OF_LIST(),
> };
> @@ -4802,8 +4802,12 @@ static void vtd_init(IntelIOMMUState *s)
> }
>
> /* TODO: read cap/ecap from host to decide which cap to be exposed. */
> - if (s->scalable_mode) {
> + if (s->scalable_mode && !s->scalable_modern) {
> s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_SLTS;
> + } else if (s->scalable_mode && s->scalable_modern) {
> + s->ecap |= VTD_ECAP_SMTS | VTD_ECAP_SRS | VTD_ECAP_PASID
> + | VTD_ECAP_FLTS | VTD_ECAP_PSS | VTD_ECAP_VCS;
> + s->vccap |= VTD_VCCAP_PAS;
> }
>
> vtd_reset_caches(s);
> @@ -4935,6 +4939,27 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
> return false;
> }
>
> + if (s->scalable_mode_str &&
> + (strcmp(s->scalable_mode_str, "modern") &&
> + strcmp(s->scalable_mode_str, "legacy"))) {

The 'off' check is missing?

> + error_setg(errp, "Invalid x-scalable-mode config,"
> + "Please use \"modern\", \"legacy\" or \"off\"");
> + return false;
> + }
> +
> + if (s->scalable_mode_str &&
> + !strcmp(s->scalable_mode_str, "legacy")) {
> + s->scalable_mode = true;
> + s->scalable_modern = false;
> + } else if (s->scalable_mode_str &&
> + !strcmp(s->scalable_mode_str, "modern")) {
> + s->scalable_mode = true;
> + s->scalable_modern = true;
> + } else {
> + s->scalable_mode = false;
> + s->scalable_modern = false;
> + }
> +
> return true;
> }
>
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index b5507ce..52b25ff 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -196,8 +196,12 @@
> #define VTD_ECAP_PT (1ULL << 6)
> #define VTD_ECAP_MHMV (15ULL << 20)
> #define VTD_ECAP_SRS (1ULL << 31)
> +#define VTD_ECAP_PSS (19ULL << 35)
> +#define VTD_ECAP_PASID (1ULL << 40)
> #define VTD_ECAP_SMTS (1ULL << 43)
> +#define VTD_ECAP_VCS (1ULL << 44)
> #define VTD_ECAP_SLTS (1ULL << 46)
> +#define VTD_ECAP_FLTS (1ULL << 47)
>
> /* CAP_REG */
> /* (offset >> 4) << 24 */
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 9782ac4..07494d4 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -268,6 +268,8 @@ struct IntelIOMMUState {
>
> bool caching_mode; /* RO - is cap CM enabled? */
> bool scalable_mode; /* RO - is Scalable Mode supported? */
> + char *scalable_mode_str; /* RO - admin's Scalable Mode config */
> + bool scalable_modern; /* RO - is modern SM supported? */
>
> dma_addr_t root; /* Current root table pointer */
> bool root_scalable; /* Type of root table (scalable or not) */
> --
> 2.7.4
>

--
Peter Xu