|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v5 23/30] ARM: vITS: handle MAPTI command
On Thu, 6 Apr 2017, Andre Przywara wrote:
> The MAPTI commands associates a DeviceID/EventID pair with a LPI/CPU
> pair and actually instantiates LPI interrupts.
> We connect the already allocated host LPI to this virtual LPI, so that
> any triggering LPI on the host can be quickly forwarded to a guest.
> Beside entering the VCPU and the virtual LPI number in the respective
> host LPI entry, we also initialize and add the already allocated
> struct pending_irq to our radix tree, so that we can now easily find it
> by its virtual LPI number.
> To be able to later find the targetting VCPU for any given LPI without
> having to walk *all* ITS tables, we store the VCPU ID in the pending_irq
> struct as well.
> This exports the vgic_init_pending_irq() function to be able to
> initialize a new struct pending_irq.
> As write_itte() is now eventually used, we can now add the static tag.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
> xen/arch/arm/gic-v3-its.c | 74 ++++++++++++++++++++++++++++++++++++++
> xen/arch/arm/gic-v3-lpi.c | 18 ++++++++++
> xen/arch/arm/vgic-v3-its.c | 76
> ++++++++++++++++++++++++++++++++++++++--
> xen/arch/arm/vgic.c | 2 +-
> xen/include/asm-arm/gic_v3_its.h | 6 ++++
> xen/include/asm-arm/vgic.h | 2 ++
> 6 files changed, 175 insertions(+), 3 deletions(-)
>
> diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
> index 76b0316..d970119 100644
> --- a/xen/arch/arm/gic-v3-its.c
> +++ b/xen/arch/arm/gic-v3-its.c
> @@ -777,6 +777,80 @@ out:
> return ret;
> }
>
> +/* Must be called with the its_device_lock held. */
> +static struct its_devices *get_its_device(struct domain *d, paddr_t
> vdoorbell,
> + uint32_t vdevid)
> +{
> + struct rb_node *node = d->arch.vgic.its_devices.rb_node;
> + struct its_devices *dev;
> +
> + ASSERT(spin_is_locked(&d->arch.vgic.its_devices_lock));
> +
> + while (node)
> + {
> + int cmp;
> +
> + dev = rb_entry(node, struct its_devices, rbnode);
> + cmp = compare_its_guest_devices(dev, vdoorbell, vdevid);
> +
> + if ( !cmp )
> + return dev;
> +
> + if ( cmp > 0 )
> + node = node->rb_left;
> + else
> + node = node->rb_right;
> + }
> +
> + return NULL;
> +}
> +
> +static uint32_t get_host_lpi(struct its_devices *dev, uint32_t eventid)
> +{
> + uint32_t host_lpi = 0;
> +
> + if ( dev && (eventid < dev->eventids) )
> + host_lpi = dev->host_lpi_blocks[eventid / LPI_BLOCK] +
> + (eventid % LPI_BLOCK);
> +
> + return host_lpi;
> +}
> +
> +/*
> + * Connects the event ID for an already assigned device to the given
> VCPU/vLPI
> + * pair. The corresponding physical LPI is already mapped on the host side
> + * (when assigning the physical device to the guest), so we just connect the
> + * target VCPU/vLPI pair to that interrupt to inject it properly if it fires.
> + * Returns a pointer to the already allocated struct pending_irq that is
> + * meant to be used by that event.
> + */
> +struct pending_irq *gicv3_assign_guest_event(struct domain *d,
> + paddr_t vdoorbell_address,
> + uint32_t vdevid, uint32_t
> veventid,
> + struct vcpu *v, uint32_t
> virt_lpi)
> +{
> + struct its_devices *dev;
> + struct pending_irq *pirq = NULL;
> + uint32_t host_lpi = 0;
> +
> + spin_lock(&d->arch.vgic.its_devices_lock);
> + dev = get_its_device(d, vdoorbell_address, vdevid);
> + if ( dev )
> + {
> + host_lpi = get_host_lpi(dev, veventid);
> + pirq = &dev->pend_irqs[veventid];
> + }
> + spin_unlock(&d->arch.vgic.its_devices_lock);
> +
> + if ( !host_lpi || !pirq )
> + return NULL;
> +
> + gicv3_lpi_update_host_entry(host_lpi, d->domain_id,
> + v ? v->vcpu_id : INVALID_VCPU_ID, virt_lpi);
> +
> + return pirq;
> +}
> +
> /* Scan the DT for any ITS nodes and create a list of host ITSes out of it.
> */
> void gicv3_its_dt_init(const struct dt_device_node *node)
> {
> diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
> index 7d20986..c997ed5 100644
> --- a/xen/arch/arm/gic-v3-lpi.c
> +++ b/xen/arch/arm/gic-v3-lpi.c
> @@ -216,6 +216,24 @@ void gicv3_do_LPI(unsigned int lpi)
> rcu_unlock_domain(d);
> }
>
> +void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
> + unsigned int vcpu_id, uint32_t virt_lpi)
> +{
> + union host_lpi *hlpip, hlpi;
> +
> + ASSERT(host_lpi >= LPI_OFFSET);
> +
> + host_lpi -= LPI_OFFSET;
> +
> + hlpip = &lpi_data.host_lpis[host_lpi / HOST_LPIS_PER_PAGE][host_lpi %
> HOST_LPIS_PER_PAGE];
> +
> + hlpi.virt_lpi = virt_lpi;
> + hlpi.dom_id = domain_id;
> + hlpi.vcpu_id = vcpu_id;
> +
> + write_u64_atomic(&hlpip->data, hlpi.data);
> +}
> +
> static int gicv3_lpi_allocate_pendtable(uint64_t *reg)
> {
> uint64_t val;
> diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
> index 0372ed0..079dd44 100644
> --- a/xen/arch/arm/vgic-v3-its.c
> +++ b/xen/arch/arm/vgic-v3-its.c
> @@ -275,8 +275,8 @@ static bool write_itte_locked(struct virt_its *its,
> uint32_t devid,
> * This function takes care of the locking by taking the its_lock itself, so
> * a caller shall not hold this. Before returning, the lock is dropped again.
> */
> -bool write_itte(struct virt_its *its, uint32_t devid, uint32_t evid,
> - uint32_t collid, uint32_t vlpi, struct vcpu **vcpu_ptr)
> +static bool write_itte(struct virt_its *its, uint32_t devid, uint32_t evid,
> + uint32_t collid, uint32_t vlpi, struct vcpu
> **vcpu_ptr)
> {
> bool ret;
>
> @@ -440,6 +440,74 @@ static int its_handle_mapd(struct virt_its *its,
> uint64_t *cmdptr)
> return ret;
> }
>
> +static int its_handle_mapti(struct virt_its *its, uint64_t *cmdptr)
> +{
> + uint32_t devid = its_cmd_get_deviceid(cmdptr);
> + uint32_t eventid = its_cmd_get_id(cmdptr);
> + uint32_t intid = its_cmd_get_physical_id(cmdptr), _intid;
> + uint16_t collid = its_cmd_get_collection(cmdptr);
> + struct pending_irq *pirq;
> + struct vcpu *vcpu = NULL;
> + int ret = 0;
> +
> + if ( its_cmd_get_command(cmdptr) == GITS_CMD_MAPI )
> + intid = eventid;
> +
> + spin_lock(&its->its_lock);
> + /*
> + * Check whether there is a valid existing mapping. If yes, behavior is
> + * unpredictable, we choose to ignore this command here.
> + * This makes sure we start with a pristine pending_irq below.
> + */
> + if ( read_itte_locked(its, devid, eventid, &vcpu, &_intid) &&
> + _intid != INVALID_LPI )
> + {
> + spin_unlock(&its->its_lock);
> + return -1;
> + }
> +
> + /* Enter the mapping in our virtual ITS tables. */
> + if ( !write_itte_locked(its, devid, eventid, collid, intid, &vcpu) )
> + {
> + spin_unlock(&its->its_lock);
> + return -1;
> + }
> +
> + spin_unlock(&its->its_lock);
> +
> + /*
> + * Connect this virtual LPI to the corresponding host LPI, which is
> + * determined by the same device ID and event ID on the host side.
> + * This returns us the corresponding, still unused pending_irq.
> + */
> + pirq = gicv3_assign_guest_event(its->d, its->doorbell_address,
> + devid, eventid, vcpu, intid);
> + if ( !pirq )
> + return -1;
> +
> + vgic_init_pending_irq(pirq, intid);
> +
> + /*
> + * Now read the guest's property table to initialize our cached state.
> + * It can't fire at this time, because it is not known to the host yet.
> + */
> + ret = update_lpi_property(its->d, intid, pirq);
> + if ( ret )
> + return ret;
> +
> + pirq->vcpu_id = vcpu->vcpu_id;
> +
> + /*
> + * Now insert the pending_irq into the domain's LPI tree, so that
> + * it becomes live.
> + */
> + write_lock(&its->d->arch.vgic.pend_lpi_tree_lock);
> + radix_tree_insert(&its->d->arch.vgic.pend_lpi_tree, intid, pirq);
> + write_unlock(&its->d->arch.vgic.pend_lpi_tree_lock);
It looks like the whole allocation, starting from
gicv3_assign_guest_event, needs to be protected by pend_lpi_tree_lock.
Otherwise we risk allocating the same struct twice? Or that is not
possible thanks to the vcmd_lock (because for two struct pending_irq to
clash they need to belong to the same vits)?
> + return 0;
> +}
> +
> #define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12)
>
> /*
> @@ -480,6 +548,10 @@ static int vgic_its_handle_cmds(struct domain *d, struct
> virt_its *its)
> case GITS_CMD_MAPD:
> ret = its_handle_mapd(its, command);
> break;
> + case GITS_CMD_MAPI:
> + case GITS_CMD_MAPTI:
> + ret = its_handle_mapti(its, command);
> + break;
> case GITS_CMD_SYNC:
> /* We handle ITS commands synchronously, so we ignore SYNC. */
> break;
> diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
> index 9b0dc3d..cb1666b 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -61,7 +61,7 @@ struct vgic_irq_rank *vgic_rank_irq(struct vcpu *v,
> unsigned int irq)
> return vgic_get_rank(v, rank);
> }
>
> -static void vgic_init_pending_irq(struct pending_irq *p, unsigned int virq)
> +void vgic_init_pending_irq(struct pending_irq *p, unsigned int virq)
> {
> INIT_LIST_HEAD(&p->inflight);
> INIT_LIST_HEAD(&p->lr_queue);
> diff --git a/xen/include/asm-arm/gic_v3_its.h
> b/xen/include/asm-arm/gic_v3_its.h
> index d3f393f..30aa1ef 100644
> --- a/xen/include/asm-arm/gic_v3_its.h
> +++ b/xen/include/asm-arm/gic_v3_its.h
> @@ -174,6 +174,12 @@ int gicv3_its_map_guest_device(struct domain *d,
> int gicv3_allocate_host_lpi_block(struct domain *d, uint32_t *first_lpi);
> void gicv3_free_host_lpi_block(uint32_t first_lpi);
>
> +struct pending_irq *gicv3_assign_guest_event(struct domain *d, paddr_t
> doorbell,
> + uint32_t devid, uint32_t
> eventid,
> + struct vcpu *v, uint32_t
> virt_lpi);
> +void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
> + unsigned int vcpu_id, uint32_t virt_lpi);
> +
> #else
>
> static LIST_HEAD(host_its_list);
> diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
> index 2371960..074afe4 100644
> --- a/xen/include/asm-arm/vgic.h
> +++ b/xen/include/asm-arm/vgic.h
> @@ -83,6 +83,7 @@ struct pending_irq
> * TODO: when implementing irq migration, taking only the current
> * vgic lock is not going to be enough. */
> struct list_head lr_queue;
> + uint16_t vcpu_id; /* The VCPU for an LPI. */
> };
>
> #define NR_INTERRUPT_PER_RANK 32
> @@ -303,6 +304,7 @@ extern struct vcpu *vgic_get_target_vcpu(struct vcpu *v,
> unsigned int virq);
> extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int virq);
> extern void vgic_vcpu_inject_spi(struct domain *d, unsigned int virq);
> extern void vgic_clear_pending_irqs(struct vcpu *v);
> +extern void vgic_init_pending_irq(struct pending_irq *p, unsigned int virq);
> extern struct pending_irq *irq_to_pending(struct vcpu *v, unsigned int irq);
> extern struct pending_irq *spi_to_pending(struct domain *d, unsigned int
> irq);
> extern struct vgic_irq_rank *vgic_rank_offset(struct vcpu *v, int b, int n,
> int s);
> --
> 2.8.2
>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |