Hi Leonid,
Leonid Komarianskyi <leonid_komarians...@epam.com> writes:
> This change introduces resource management in the VGIC to handle
> extended SPIs introduced in GICv3.1. The pending_irqs and
> allocated_irqs arrays are resized to support the required
> number of eSPIs, based on what is supported by the hardware and
> requested by the guest. A new field, ext_shared_irqs, is added
> to the VGIC structure to store information about eSPIs, similar
> to how shared_irqs is used for regular SPIs.
>
> Since the eSPI range starts at INTID 4096 and INTIDs between 1025
> and 4095 are reserved, helper macros are introduced to simplify the
> transformation of indices and to enable easier access to eSPI-specific
> resources. These changes prepare the VGIC for processing eSPIs as
> required by future functionality.
>
> The initialization and deinitialization paths for vgic have been updated
> to allocate and free these resources appropriately. Additionally,
> updated handling of INTIDs greater than 1024, passed from the toolstack
> during domain creation, and verification logic ensures only valid SPI or
> eSPI INTIDs are used.
>
> The existing SPI behavior remains unaffected when guests do not request
> eSPIs, GIC hardware does not support them, or the CONFIG_GICV3_ESPI
> option is disabled.
>
> Signed-off-by: Leonid Komarianskyi <leonid_komarians...@epam.com>
>
> ---
> Changes for V6:
> - introduced a new function for index to virq conversion, idx_to_virq.
> This allows the removal of eSPI-specific functions and enables the
> reuse of existing code for regular SPIs
> - fixed the return value of vgic_allocate_virq in the case of eSPI
> - updated the error message in route_irq_to_guest(). To simplify it and
> avoid overcomplicating with INTID ranges, propose removing the
> information about the max number of IRQs
> - fixed eSPI rank initialization to avoid using EXT_RANK_IDX2NUM for
> converting the eSPI rank to the extended range
> - updated the recalculation logic to avoid the nr_spis > 1020 -
> NR_LOCAL_IRQS check when nr_spis is reassigned in the case of eSPI
> - fixed formatting issues for macros
> - minor change: changed the macros ESPI_INTID2IDX and ESPI_IDX2INTID
> into appropriate inline functions introduced in the previous patch
> - minor change: changed int to unsigned int for nr_espis
>
> Changes in V5:
> - removed the has_espi field because it can be determined by checking
> whether domain->arch.vgic.nr_espis is zero or not
> - since vgic_ext_rank_offset is not used in this patch, it has been
> moved to the appropriate patch in the patch series, which implements
> vgic eSPI registers emulation and requires this function
> - removed ifdefs for eSPI-specific macros to reduce the number of ifdefs
> and code duplication in further changes
> - fixed minor nit: used %pd for printing domain with its ID
>
> Changes in V4:
> - added has_espi field to simplify determining whether a domain is able
> to operate with eSPI
> - fixed formatting issues and misspellings
>
> Changes in V3:
> - fixed formatting for lines with more than 80 symbols
> - introduced helper functions to be able to use stubs in case of
> CONFIG_GICV3_ESPI disabled, and as a result, reduce the number of
> #ifdefs
> - fixed checks for nr_spis in domain_vgic_init
> - updated comment about nr_spis adjustments with dom0less mention
> - moved comment with additional explanations before checks
> - used unsigned int for indexes since they cannot be negative
> - removed unnecessary parentheses
> - move vgic_ext_rank_offset to the below ifdef guard, to reduce the
> number of ifdefs
>
> Changes in V2:
> - change is_espi_rank to is_valid_espi_rank to verify whether the array
> element ext_shared_irqs exists. The previous version, is_espi_rank,
> only checked if the rank index was less than the maximum possible eSPI
> rank index, but this could potentially result in accessing a
> non-existing array element. To address this, is_valid_espi_rank was
> introduced, which ensures that the required eSPI rank exists
> - move gic_number_espis to
> xen/arm: gicv3: implement handling of GICv3.1 eSPI
> - update vgic_is_valid_irq checks to allow operating with eSPIs
> - remove redundant newline in vgic_allocate_virq
> ---
> xen/arch/arm/include/asm/vgic.h | 12 +++
> xen/arch/arm/irq.c | 3 +-
> xen/arch/arm/vgic.c | 174 ++++++++++++++++++++++++++++++--
> 3 files changed, 176 insertions(+), 13 deletions(-)
>
> diff --git a/xen/arch/arm/include/asm/vgic.h b/xen/arch/arm/include/asm/vgic.h
> index 3e7cbbb196..1cf0a05832 100644
> --- a/xen/arch/arm/include/asm/vgic.h
> +++ b/xen/arch/arm/include/asm/vgic.h
> @@ -146,6 +146,10 @@ struct vgic_dist {
> int nr_spis; /* Number of SPIs */
> unsigned long *allocated_irqs; /* bitmap of IRQs allocated */
> struct vgic_irq_rank *shared_irqs;
> +#ifdef CONFIG_GICV3_ESPI
> + struct vgic_irq_rank *ext_shared_irqs;
> + unsigned int nr_espis; /* Number of extended SPIs */
> +#endif
> /*
> * SPIs are domain global, SGIs and PPIs are per-VCPU and stored in
> * struct arch_vcpu.
> @@ -243,6 +247,14 @@ struct vgic_ops {
> /* Number of ranks of interrupt registers for a domain */
> #define DOMAIN_NR_RANKS(d) (((d)->arch.vgic.nr_spis+31)/32)
>
> +#ifdef CONFIG_GICV3_ESPI
> +#define DOMAIN_NR_EXT_RANKS(d) (((d)->arch.vgic.nr_espis + 31) / 32)
> +#endif
> +#define EXT_RANK_MIN (ESPI_BASE_INTID / 32)
> +#define EXT_RANK_MAX ((ESPI_MAX_INTID + 31) / 32)
> +#define EXT_RANK_NUM2IDX(num) ((num) - EXT_RANK_MIN)
> +#define EXT_RANK_IDX2NUM(idx) ((idx) + EXT_RANK_MIN)
> +
> #define vgic_lock(v) spin_lock_irq(&(v)->domain->arch.vgic.lock)
> #define vgic_unlock(v) spin_unlock_irq(&(v)->domain->arch.vgic.lock)
>
> diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
> index c934d39bf6..c2f1ceb91f 100644
> --- a/xen/arch/arm/irq.c
> +++ b/xen/arch/arm/irq.c
> @@ -494,8 +494,7 @@ int route_irq_to_guest(struct domain *d, unsigned int
> virq,
> if ( !vgic_is_valid_line(d, virq) )
> {
> printk(XENLOG_G_ERR
> - "the vIRQ number %u is too high for domain %u (max = %u)\n",
> - irq, d->domain_id, vgic_num_irqs(d));
> + "invalid vIRQ number %u for domain %pd\n", irq, d);
> return -EINVAL;
> }
>
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index 2bbf4d99aa..b42aee8d0c 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -25,11 +25,61 @@
> #include <asm/vgic.h>
>
>
> +static inline unsigned int idx_to_virq(struct domain *d, unsigned int idx)
> +{
> + if ( idx >= vgic_num_irqs(d) )
> + return espi_idx_to_intid(idx - vgic_num_irqs(d));
> +
> + return idx;
> +}
> +
> bool vgic_is_valid_line(struct domain *d, unsigned int virq)
> {
> +#ifdef CONFIG_GICV3_ESPI
> + if ( virq >= ESPI_BASE_INTID &&
> + virq < espi_idx_to_intid(d->arch.vgic.nr_espis) )
> + return true;
> +#endif
> +
> return virq < vgic_num_irqs(d);
> }
>
> +#ifdef CONFIG_GICV3_ESPI
> +/*
> + * Since eSPI indexes start from 4096 and numbers from 1024 to
> + * 4095 are forbidden, we need to check both lower and upper
> + * limits for ranks.
> + */
> +static inline bool is_valid_espi_rank(struct domain *d, unsigned int rank)
> +{
> + return rank >= EXT_RANK_MIN &&
> + EXT_RANK_NUM2IDX(rank) < DOMAIN_NR_EXT_RANKS(d);
> +}
> +
> +static inline struct vgic_irq_rank *vgic_get_espi_rank(struct vcpu *v,
> + unsigned int rank)
> +{
> + return &v->domain->arch.vgic.ext_shared_irqs[EXT_RANK_NUM2IDX(rank)];
> +}
> +
> +#else
> +static inline bool is_valid_espi_rank(struct domain *d, unsigned int rank)
> +{
> + return false;
> +}
> +
> +/*
> + * This function is stub and will not be called if CONFIG_GICV3_ESPI=n,
> + * because in this case, is_valid_espi_rank will always return false.
> + */
> +static inline struct vgic_irq_rank *vgic_get_espi_rank(struct vcpu *v,
> + unsigned int rank)
> +{
> + ASSERT_UNREACHABLE();
> + return NULL;
> +}
> +#endif
> +
> static inline struct vgic_irq_rank *vgic_get_rank(struct vcpu *v,
> unsigned int rank)
> {
> @@ -37,6 +87,8 @@ static inline struct vgic_irq_rank *vgic_get_rank(struct
> vcpu *v,
> return v->arch.vgic.private_irqs;
> else if ( rank <= DOMAIN_NR_RANKS(v->domain) )
> return &v->domain->arch.vgic.shared_irqs[rank - 1];
> + else if ( is_valid_espi_rank(v->domain, rank) )
> + return vgic_get_espi_rank(v, rank);
> else
> return NULL;
> }
> @@ -117,6 +169,54 @@ int domain_vgic_register(struct domain *d, unsigned int
> *mmio_count)
> return 0;
> }
>
> +#ifdef CONFIG_GICV3_ESPI
> +static unsigned int vgic_num_spi_lines(struct domain *d)
> +{
> + return d->arch.vgic.nr_spis + d->arch.vgic.nr_espis;
> +}
> +
> +static int init_vgic_espi(struct domain *d)
> +{
> + unsigned int i, idx;
> +
> + if ( d->arch.vgic.nr_espis == 0 )
> + return 0;
> +
> + d->arch.vgic.ext_shared_irqs =
> + xzalloc_array(struct vgic_irq_rank, DOMAIN_NR_EXT_RANKS(d));
> + if ( d->arch.vgic.ext_shared_irqs == NULL )
> + return -ENOMEM;
> +
> + for ( i = d->arch.vgic.nr_spis, idx = 0;
> + i < vgic_num_spi_lines(d); i++, idx++ )
> + vgic_init_pending_irq(&d->arch.vgic.pending_irqs[i],
> + espi_idx_to_intid(idx));
> +
> + for ( i = 0; i < DOMAIN_NR_EXT_RANKS(d); i++ )
> + vgic_rank_init(&d->arch.vgic.ext_shared_irqs[i],
> + EXT_RANK_IDX2NUM(i), 0);
> +
> + return 0;
> +}
> +
> +#else
> +static int init_vgic_espi(struct domain *d)
> +{
> + return 0;
> +}
> +
> +static unsigned int vgic_num_spi_lines(struct domain *d)
> +{
> + return d->arch.vgic.nr_spis;
> +}
> +
> +#endif
> +
> +static unsigned int vgic_num_alloc_irqs(struct domain *d)
> +{
> + return vgic_num_spi_lines(d) + NR_LOCAL_IRQS;
This is good that you are using NR_LOCAL_IRQS here.
> +}
> +
> int domain_vgic_init(struct domain *d, unsigned int nr_spis)
> {
> int i;
> @@ -133,7 +233,39 @@ int domain_vgic_init(struct domain *d, unsigned int
> nr_spis)
>
> /* Limit the number of virtual SPIs supported to (1020 - 32) = 988 */
> if ( nr_spis > (1020 - NR_LOCAL_IRQS) )
> +#ifndef CONFIG_GICV3_ESPI
> return -EINVAL;
> +#else
> + {
> + /*
> + * During domain creation, the dom0less DomUs code or toolstack
> + * specifies the maximum INTID, which is defined in the domain
> + * config subtracted by 32 to cover the local IRQs (please see
> + * the comment to VGIC_DEF_NR_SPIS). To compute the actual number
> + * of eSPI that will be usable for, add back 32.
> + */
> + nr_spis += 32;
I think that it is better to use NR_LOCAL_IRQS here.
(Also, I just noticed the same problem as with documentation, meaning
that nr_spis actually does not represent number of SPIs anymore, and
behaves more like max_spi, but let's set this issue aside for now)
> + if ( nr_spis > espi_idx_to_intid(NR_ESPI_IRQS) )
> + return -EINVAL;
> +
> + if ( nr_spis >= ESPI_BASE_INTID )
> + {
> + unsigned int nr_espis = min(nr_spis - ESPI_BASE_INTID, 1024U);
> +
> + /* Verify if GIC HW can handle provided INTID */
> + if ( nr_espis > gic_number_espis() )
> + return -EINVAL;
> +
> + d->arch.vgic.nr_espis = nr_espis;
> + /* Set the maximum available number for regular SPIs */
> + nr_spis = VGIC_DEF_NR_SPIS;
> + }
> + else
> + {
> + return -EINVAL;
> + }
> + }
> +#endif
>
> d->arch.vgic.nr_spis = nr_spis;
>
> @@ -145,7 +277,7 @@ int domain_vgic_init(struct domain *d, unsigned int
> nr_spis)
> return -ENOMEM;
>
> d->arch.vgic.pending_irqs =
> - xzalloc_array(struct pending_irq, d->arch.vgic.nr_spis);
> + xzalloc_array(struct pending_irq, vgic_num_spi_lines(d));
> if ( d->arch.vgic.pending_irqs == NULL )
> return -ENOMEM;
>
> @@ -156,12 +288,16 @@ int domain_vgic_init(struct domain *d, unsigned int
> nr_spis)
> for ( i = 0; i < DOMAIN_NR_RANKS(d); i++ )
> vgic_rank_init(&d->arch.vgic.shared_irqs[i], i + 1, 0);
>
> + ret = init_vgic_espi(d);
> + if ( ret )
> + return ret;
> +
> ret = d->arch.vgic.handler->domain_init(d);
> if ( ret )
> return ret;
>
> d->arch.vgic.allocated_irqs =
> - xzalloc_array(unsigned long, BITS_TO_LONGS(vgic_num_irqs(d)));
> + xzalloc_array(unsigned long, BITS_TO_LONGS(vgic_num_alloc_irqs(d)));
> if ( !d->arch.vgic.allocated_irqs )
> return -ENOMEM;
>
> @@ -182,9 +318,12 @@ void domain_vgic_free(struct domain *d)
> int i;
> int ret;
>
> - for ( i = 0; i < (d->arch.vgic.nr_spis); i++ )
> + for ( i = 32; i < vgic_num_alloc_irqs(d); i++ )
s/32/NR_LOCAL_IRQS
> {
> - struct pending_irq *p = spi_to_pending(d, i + 32);
> + struct pending_irq *p;
> + unsigned int virq = idx_to_virq(d, i);
> +
> + p = spi_to_pending(d, virq);
>
> if ( p->desc )
> {
> @@ -198,6 +337,9 @@ void domain_vgic_free(struct domain *d)
> if ( d->arch.vgic.handler )
> d->arch.vgic.handler->domain_free(d);
> xfree(d->arch.vgic.shared_irqs);
> +#ifdef CONFIG_GICV3_ESPI
> + xfree(d->arch.vgic.ext_shared_irqs);
> +#endif
> xfree(d->arch.vgic.pending_irqs);
> xfree(d->arch.vgic.allocated_irqs);
> }
> @@ -323,10 +465,12 @@ void arch_move_irqs(struct vcpu *v)
> */
> ASSERT(!is_lpi(vgic_num_irqs(d) - 1));
>
> - for ( i = 32; i < vgic_num_irqs(d); i++ )
> + for ( i = 32; i < vgic_num_alloc_irqs(d); i++ )
It is great idea to start using NR_LOCAL_IRQS here instead of hard-coded 32.
> {
> - v_target = vgic_get_target_vcpu(v, i);
> - p = irq_to_pending(v_target, i);
> + unsigned int virq = idx_to_virq(d, i);
> +
> + v_target = vgic_get_target_vcpu(v, virq);
> + p = irq_to_pending(v_target, virq);
>
> if ( v_target == v && !test_bit(GIC_IRQ_GUEST_MIGRATING, &p->status)
> )
> irq_set_affinity(p->desc, cpu_mask);
> @@ -539,7 +683,7 @@ struct pending_irq *irq_to_pending(struct vcpu *v,
> unsigned int irq)
> else if ( is_lpi(irq) )
> n = v->domain->arch.vgic.handler->lpi_to_pending(v->domain, irq);
> else
> - n = &v->domain->arch.vgic.pending_irqs[irq - 32];
> + n = spi_to_pending(v->domain, irq);
> return n;
> }
>
> @@ -547,7 +691,12 @@ struct pending_irq *spi_to_pending(struct domain *d,
> unsigned int irq)
> {
> ASSERT(irq >= NR_LOCAL_IRQS);
>
> - return &d->arch.vgic.pending_irqs[irq - 32];
> + if ( is_espi(irq) )
> + irq = espi_intid_to_idx(irq) + d->arch.vgic.nr_spis;
> + else
> + irq -= 32;
s/32/NR_LOCAL_IRQS
Also, I want you to consider adding local variable "idx" instead of
reusing "irq" parameter.
> +
> + return &d->arch.vgic.pending_irqs[irq];
> }
>
> void vgic_clear_pending_irqs(struct vcpu *v)
> @@ -668,6 +817,9 @@ bool vgic_reserve_virq(struct domain *d, unsigned int
> virq)
> if ( !vgic_is_valid_line(d, virq) )
> return false;
>
> + if ( is_espi(virq) )
> + virq = espi_intid_to_idx(virq) + vgic_num_irqs(d);
Here as well. It is very confusing when you are updating virq with a
value that does not corresponds in IRQ number anymore.
> +
> return !test_and_set_bit(virq, d->arch.vgic.allocated_irqs);
> }
>
> @@ -685,7 +837,7 @@ int vgic_allocate_virq(struct domain *d, bool spi)
> else
> {
> first = 32;
> - end = vgic_num_irqs(d);
> + end = vgic_num_alloc_irqs(d);
> }
>
> /*
> @@ -700,7 +852,7 @@ int vgic_allocate_virq(struct domain *d, bool spi)
> }
> while ( test_and_set_bit(virq, d->arch.vgic.allocated_irqs) );
>
> - return virq;
> + return idx_to_virq(d, virq);
> }
>
> void vgic_free_virq(struct domain *d, unsigned int virq)
--
WBR, Volodymyr
