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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC PATCH 11/24] ARM: vGICv3: handle virtual LPI pending and property tables
On Wed, Sep 28, 2016 at 11:54 PM, Andre Przywara <andre.przywara@xxxxxxx> wrote:
> Allow a guest to provide the address and size for the memory regions
> it has reserved for the GICv3 pending and property tables.
> We sanitise the various fields of the respective redistributor
> registers and map those pages into Xen's address space to have easy
> access.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> xen/arch/arm/vgic-v3.c | 189
> ++++++++++++++++++++++++++++++++++++++----
> xen/arch/arm/vgic.c | 4 +
> xen/include/asm-arm/domain.h | 7 +-
> xen/include/asm-arm/gic-its.h | 10 ++-
> xen/include/asm-arm/vgic.h | 3 +
> 5 files changed, 197 insertions(+), 16 deletions(-)
>
> diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
> index e9b6490..8fe8386 100644
> --- a/xen/arch/arm/vgic-v3.c
> +++ b/xen/arch/arm/vgic-v3.c
> @@ -20,12 +20,14 @@
>
> #include <xen/bitops.h>
> #include <xen/config.h>
> +#include <xen/domain_page.h>
> #include <xen/lib.h>
> #include <xen/init.h>
> #include <xen/softirq.h>
> #include <xen/irq.h>
> #include <xen/sched.h>
> #include <xen/sizes.h>
> +#include <xen/vmap.h>
> #include <asm/current.h>
> #include <asm/mmio.h>
> #include <asm/gic_v3_defs.h>
> @@ -228,12 +230,14 @@ static int __vgic_v3_rdistr_rd_mmio_read(struct vcpu
> *v, mmio_info_t *info,
> goto read_reserved;
>
> case VREG64(GICR_PROPBASER):
> - /* LPI's not implemented */
> - goto read_as_zero_64;
> + if ( !vgic_reg64_check_access(dabt) ) goto bad_width;
> + *r = vgic_reg64_extract(v->domain->arch.vgic.rdist_propbase, info);
> + return 1;
>
> case VREG64(GICR_PENDBASER):
> - /* LPI's not implemented */
> - goto read_as_zero_64;
> + if ( !vgic_reg64_check_access(dabt) ) goto bad_width;
> + *r = vgic_reg64_extract(v->arch.vgic.rdist_pendbase, info);
> + return 1;
>
> case 0x0080:
> goto read_reserved;
> @@ -301,11 +305,6 @@ bad_width:
> domain_crash_synchronous();
> return 0;
>
> -read_as_zero_64:
> - if ( !vgic_reg64_check_access(dabt) ) goto bad_width;
> - *r = 0;
> - return 1;
> -
> read_as_zero_32:
> if ( dabt.size != DABT_WORD ) goto bad_width;
> *r = 0;
> @@ -330,11 +329,149 @@ read_unknown:
> return 1;
> }
>
> +static uint64_t vgic_sanitise_field(uint64_t reg, uint64_t field_mask,
> + int field_shift,
> + uint64_t (*sanitise_fn)(uint64_t))
> +{
> + uint64_t field = (reg & field_mask) >> field_shift;
> +
> + field = sanitise_fn(field) << field_shift;
> + return (reg & ~field_mask) | field;
> +}
> +
> +/* We want to avoid outer shareable. */
> +static uint64_t vgic_sanitise_shareability(uint64_t field)
> +{
> + switch (field) {
> + case GIC_BASER_OuterShareable:
> + return GIC_BASER_InnerShareable;
> + default:
> + return field;
> + }
> +}
> +
> +/* Avoid any inner non-cacheable mapping. */
> +static uint64_t vgic_sanitise_inner_cacheability(uint64_t field)
> +{
> + switch (field) {
> + case GIC_BASER_CACHE_nCnB:
> + case GIC_BASER_CACHE_nC:
> + return GIC_BASER_CACHE_RaWb;
> + default:
> + return field;
> + }
> +}
> +
> +/* Non-cacheable or same-as-inner are OK. */
> +static uint64_t vgic_sanitise_outer_cacheability(uint64_t field)
> +{
> + switch (field) {
> + case GIC_BASER_CACHE_SameAsInner:
> + case GIC_BASER_CACHE_nC:
> + return field;
> + default:
> + return GIC_BASER_CACHE_nC;
> + }
> +}
> +
> +static uint64_t sanitize_propbaser(uint64_t reg)
> +{
> + reg = vgic_sanitise_field(reg, GICR_PROPBASER_SHAREABILITY_MASK,
> + GICR_PROPBASER_SHAREABILITY_SHIFT,
> + vgic_sanitise_shareability);
> + reg = vgic_sanitise_field(reg, GICR_PROPBASER_INNER_CACHEABILITY_MASK,
> + GICR_PROPBASER_INNER_CACHEABILITY_SHIFT,
> + vgic_sanitise_inner_cacheability);
> + reg = vgic_sanitise_field(reg, GICR_PROPBASER_OUTER_CACHEABILITY_MASK,
> + GICR_PROPBASER_OUTER_CACHEABILITY_SHIFT,
> + vgic_sanitise_outer_cacheability);
> +
> + reg &= ~PROPBASER_RES0_MASK;
> + reg &= ~GENMASK(51, 48);
> + return reg;
> +}
> +
> +static uint64_t sanitize_pendbaser(uint64_t reg)
> +{
> + reg = vgic_sanitise_field(reg, GICR_PENDBASER_SHAREABILITY_MASK,
> + GICR_PENDBASER_SHAREABILITY_SHIFT,
> + vgic_sanitise_shareability);
> + reg = vgic_sanitise_field(reg, GICR_PENDBASER_INNER_CACHEABILITY_MASK,
> + GICR_PENDBASER_INNER_CACHEABILITY_SHIFT,
> + vgic_sanitise_inner_cacheability);
> + reg = vgic_sanitise_field(reg, GICR_PENDBASER_OUTER_CACHEABILITY_MASK,
> + GICR_PENDBASER_OUTER_CACHEABILITY_SHIFT,
> + vgic_sanitise_outer_cacheability);
> +
> + reg &= ~PENDBASER_RES0_MASK;
> + reg &= ~GENMASK(51, 48);
> + return reg;
> +}
> +
> +/*
> + * Allow mapping some parts of guest memory into Xen's VA space to have easy
> + * access to it. This is to allow ITS configuration data to be held in
> + * guest memory and avoid using Xen memory for that.
> + */
> +void *map_guest_pages(struct domain *d, paddr_t guest_addr, int nr_pages)
I think this file is not right place to put this generic function
> +{
> + mfn_t onepage;
> + mfn_t *pages;
> + int i;
> + void *ptr;
> +
> + /* TODO: free previous mapping, change prototype? use get-put-put? */
> +
> + guest_addr &= PAGE_MASK;
> +
> + if ( nr_pages == 1 )
> + {
> + pages = &onepage;
> + } else
> + {
> + pages = xmalloc_array(mfn_t, nr_pages);
> + if ( !pages )
> + return NULL;
> + }
> +
> + for (i = 0; i < nr_pages; i++)
> + {
> + get_page_from_gfn(d, (guest_addr >> PAGE_SHIFT) + i, NULL,
> P2M_ALLOC);
check return value of this function
> + pages[i] = _mfn((guest_addr + i * PAGE_SIZE) >> PAGE_SHIFT);
> + }
> +
> + ptr = vmap(pages, nr_pages);
> +
> + if ( nr_pages > 1 )
> + xfree(pages);
> +
> + return ptr;
> +}
> +
> +void unmap_guest_pages(void *va, int nr_pages)
same here. Can be put in generic file p2m.c?
> +{
> + paddr_t pa;
> + unsigned long i;
> +
> + if ( !va )
> + return;
> +
> + va = (void *)((uintptr_t)va & PAGE_MASK);
> + pa = virt_to_maddr(va);
can use _pa()
> +
> + vunmap(va);
> + for (i = 0; i < nr_pages; i++)
> + put_page(mfn_to_page((pa >> PAGE_SHIFT) + i));
> +
> + return;
> +}
> +
> static int __vgic_v3_rdistr_rd_mmio_write(struct vcpu *v, mmio_info_t *info,
> uint32_t gicr_reg,
> register_t r)
> {
> struct hsr_dabt dabt = info->dabt;
> + uint64_t reg;
>
> switch ( gicr_reg )
> {
> @@ -375,13 +512,37 @@ static int __vgic_v3_rdistr_rd_mmio_write(struct vcpu
> *v, mmio_info_t *info,
> case 0x0050:
> goto write_reserved;
>
> - case VREG64(GICR_PROPBASER):
> - /* LPI is not implemented */
> - goto write_ignore_64;
> + case VREG64(GICR_PROPBASER): {
> + int nr_pages;
> +
> + if ( info->dabt.size < DABT_WORD ) goto bad_width;
> + if ( v->arch.vgic.flags & VGIC_V3_LPIS_ENABLED )
> + return 1;
> +
> + reg = v->domain->arch.vgic.rdist_propbase;
> + vgic_reg64_update(®, r, info);
> + reg = sanitize_propbaser(reg);
> + v->domain->arch.vgic.rdist_propbase = reg;
>
> + nr_pages = BIT((v->domain->arch.vgic.rdist_propbase & 0x1f) + 1) -
> 8192;
should be validated against HOST_LPIS?
> + nr_pages = DIV_ROUND_UP(nr_pages, PAGE_SIZE);
> + unmap_guest_pages(v->domain->arch.vgic.proptable, nr_pages);
> + v->domain->arch.vgic.proptable = map_guest_pages(v->domain,
> + reg & GENMASK(47,
> 12),
> + nr_pages);
> + return 1;
> + }
> case VREG64(GICR_PENDBASER):
> - /* LPI is not implemented */
> - goto write_ignore_64;
> + if ( info->dabt.size < DABT_WORD ) goto bad_width;
check on VGIC_V3_LPIS_ENABLED is required
> + reg = v->arch.vgic.rdist_pendbase;
> + vgic_reg64_update(®, r, info);
> + reg = sanitize_pendbaser(reg);
> + v->arch.vgic.rdist_pendbase = reg;
> +
> + unmap_guest_pages(v->arch.vgic.pendtable, 16);
why only 16 pages are unmapped?
> + v->arch.vgic.pendtable = map_guest_pages(v->domain,
> + reg & GENMASK(47, 12), 16);
> + return 1;
>
> case 0x0080:
> goto write_reserved;
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index b961551..4d9304f 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -488,6 +488,10 @@ struct pending_irq *lpi_to_pending(struct vcpu *v,
> unsigned int lpi,
> empty->pirq.irq = lpi;
> }
>
> + /* Update the enabled status */
> + if ( gicv3_lpi_is_enabled(v->domain, lpi) )
> + set_bit(GIC_IRQ_GUEST_ENABLED, &empty->pirq.status);
> +
> return &empty->pirq;
> }
>
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> index ae8a9de..0cd3500 100644
> --- a/xen/include/asm-arm/domain.h
> +++ b/xen/include/asm-arm/domain.h
> @@ -109,6 +109,8 @@ struct arch_domain
> } *rdist_regions;
> int nr_regions; /* Number of rdist regions */
> uint32_t rdist_stride; /* Re-Distributor stride */
> + uint64_t rdist_propbase;
> + uint8_t *proptable;
> #endif
> } vgic;
>
> @@ -247,7 +249,10 @@ struct arch_vcpu
>
> /* GICv3: redistributor base and flags for this vCPU */
> paddr_t rdist_base;
> -#define VGIC_V3_RDIST_LAST (1 << 0) /* last vCPU of the rdist */
> +#define VGIC_V3_RDIST_LAST (1 << 0) /* last vCPU of the rdist */
> +#define VGIC_V3_LPIS_ENABLED (1 << 1)
> + uint64_t rdist_pendbase;
> + unsigned long *pendtable;
> uint8_t flags;
> struct list_head pending_lpi_list;
> } vgic;
> diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
> index 1f881c0..3b2e5c0 100644
> --- a/xen/include/asm-arm/gic-its.h
> +++ b/xen/include/asm-arm/gic-its.h
> @@ -139,7 +139,11 @@ int gicv3_lpi_drop_host_lpi(struct host_its *its,
>
> static inline int gicv3_lpi_get_priority(struct domain *d, uint32_t lpi)
> {
> - return GIC_PRI_IRQ;
> + return d->arch.vgic.proptable[lpi - 8192] & 0xfc;
> +}
> +static inline bool gicv3_lpi_is_enabled(struct domain *d, uint32_t lpi)
> +{
> + return d->arch.vgic.proptable[lpi - 8192] & LPI_PROP_ENABLED;
> }
>
> #else
> @@ -185,6 +189,10 @@ static inline int gicv3_lpi_get_priority(struct domain
> *d, uint32_t lpi)
> {
> return GIC_PRI_IRQ;
> }
> +static inline bool gicv3_lpi_is_enabled(struct domain *d, uint32_t lpi)
> +{
> + return false;
> +}
>
> #endif /* CONFIG_HAS_ITS */
>
> diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
> index 4e29ba6..2b216cc 100644
> --- a/xen/include/asm-arm/vgic.h
> +++ b/xen/include/asm-arm/vgic.h
> @@ -285,6 +285,9 @@ VGIC_REG_HELPERS(32, 0x3);
>
> #undef VGIC_REG_HELPERS
>
> +void *map_guest_pages(struct domain *d, paddr_t guest_addr, int nr_pages);
> +void unmap_guest_pages(void *va, int nr_pages);
> +
> enum gic_sgi_mode;
>
> /*
> --
> 2.9.0
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> https://lists.xen.org/xen-devel
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