[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v3 06/26] ARM: GICv3 ITS: introduce device mapping
Hi Andre, On Fri, Mar 31, 2017 at 11:35 PM, Andre Przywara <andre.przywara@xxxxxxx> wrote: > The ITS uses device IDs to map LPIs to a device. Dom0 will later use > those IDs, which we directly pass on to the host. > For this we have to map each device that Dom0 may request to a host > ITS device with the same identifier. > Allocate the respective memory and enter each device into an rbtree to > later be able to iterate over it or to easily teardown guests. > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> > --- > xen/arch/arm/gic-v3-its.c | 227 > +++++++++++++++++++++++++++++++++++++++ > xen/arch/arm/vgic-v3.c | 4 + > xen/include/asm-arm/domain.h | 3 + > xen/include/asm-arm/gic_v3_its.h | 23 ++++ > 4 files changed, 257 insertions(+) > > diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c > index 1ac598f..295f7dc 100644 > --- a/xen/arch/arm/gic-v3-its.c > +++ b/xen/arch/arm/gic-v3-its.c > @@ -21,6 +21,8 @@ > #include <xen/lib.h> > #include <xen/delay.h> > #include <xen/mm.h> > +#include <xen/rbtree.h> > +#include <xen/sched.h> > #include <xen/sizes.h> > #include <asm/gic.h> > #include <asm/gic_v3_defs.h> > @@ -32,6 +34,18 @@ > > LIST_HEAD(host_its_list); > > +struct its_devices { > + struct rb_node rbnode; > + struct host_its *hw_its; > + void *itt_addr; > + paddr_t guest_doorbell; /* Identifies the virtual ITS */ > + uint32_t host_devid; > + uint32_t guest_devid; > + uint32_t eventids; /* Number of event IDs (MSIs) */ > + uint32_t *host_lpi_blocks; /* Which LPIs are used on the host */ > + struct pending_irq *pend_irqs; /* One struct per event */ > +}; > + > bool gicv3_its_host_has_its(void) > { > return !list_empty(&host_its_list); > @@ -151,6 +165,26 @@ static int its_send_cmd_mapc(struct host_its *its, > uint32_t collection_id, > return its_send_command(its, cmd); > } > > +static int its_send_cmd_mapd(struct host_its *its, uint32_t deviceid, > + uint8_t size_bits, paddr_t itt_addr, bool valid) > +{ > + uint64_t cmd[4]; > + > + if ( valid ) > + { > + ASSERT(size_bits < 32); > + ASSERT(!(itt_addr & ~GENMASK_ULL(51, 8))); > + } > + cmd[0] = GITS_CMD_MAPD | ((uint64_t)deviceid << 32); > + cmd[1] = size_bits; > + cmd[2] = itt_addr; > + if ( valid ) > + cmd[2] |= GITS_VALID_BIT; > + cmd[3] = 0x00; > + > + return its_send_command(its, cmd); > +} > + > /* Set up the (1:1) collection mapping for the given host CPU. */ > int gicv3_its_setup_collection(unsigned int cpu) > { > @@ -376,6 +410,7 @@ static int gicv3_its_init_single_its(struct host_its > *hw_its) > hw_its->devid_bits = min(hw_its->devid_bits, max_its_device_bits); > if ( reg & GITS_TYPER_PTA ) > hw_its->flags |= HOST_ITS_USES_PTA; > + hw_its->itte_size = GITS_TYPER_ITT_SIZE(reg); > > for ( i = 0; i < GITS_BASER_NR_REGS; i++ ) > { > @@ -432,6 +467,197 @@ int gicv3_its_init(void) > return 0; > } > > +static int remove_mapped_guest_device(struct its_devices *dev) > +{ > + int ret; > + > + if ( dev->hw_its ) > + { > + /* MAPD also discards all events with this device ID. */ > + int ret = its_send_cmd_mapd(dev->hw_its, dev->host_devid, 0, 0, > false); > + if ( ret ) > + return ret; > + } > + > + ret = gicv3_its_wait_commands(dev->hw_its); > + if ( ret ) > + return ret; > + > + xfree(dev->itt_addr); > + xfree(dev->pend_irqs); > + xfree(dev); > + > + return 0; > +} > + > +static struct host_its *gicv3_its_find_by_doorbell(paddr_t doorbell_address) > +{ > + struct host_its *hw_its; > + > + list_for_each_entry(hw_its, &host_its_list, entry) > + { > + if ( hw_its->addr + ITS_DOORBELL_OFFSET == doorbell_address ) > + return hw_its; > + } > + > + return NULL; > +} > + > +static int compare_its_guest_devices(struct its_devices *dev, > + paddr_t doorbell, uint32_t devid) > +{ > + if ( dev->guest_doorbell < doorbell ) > + return -1; > + > + if ( dev->guest_doorbell > doorbell ) > + return 1; > + > + if ( dev->guest_devid < devid ) > + return -1; > + > + if ( dev->guest_devid > devid ) > + return 1; > + > + return 0; > +} > + > +/* > + * Map a hardware device, identified by a certain host ITS and its device ID > + * to domain d, a guest ITS (identified by its doorbell address) and device > ID. > + * Also provide the number of events (MSIs) needed for that device. > + * This does not check if this particular hardware device is already mapped > + * at another domain, it is expected that this would be done by the caller. > + */ > +int gicv3_its_map_guest_device(struct domain *d, > + paddr_t host_doorbell, uint32_t host_devid, > + paddr_t guest_doorbell, uint32_t guest_devid, > + uint32_t nr_events, bool valid) > +{ > + void *itt_addr = NULL; > + struct host_its *hw_its; > + struct its_devices *dev = NULL; > + struct rb_node **new = &d->arch.vgic.its_devices.rb_node, *parent = NULL; > + int ret = -ENOENT; > + > + hw_its = gicv3_its_find_by_doorbell(host_doorbell); > + if ( !hw_its ) > + return ret; > + > + /* check for already existing mappings */ > + spin_lock(&d->arch.vgic.its_devices_lock); > + while ( *new ) > + { > + struct its_devices *temp; > + int cmp; > + > + temp = rb_entry(*new, struct its_devices, rbnode); > + > + parent = *new; > + cmp = compare_its_guest_devices(temp, guest_doorbell, guest_devid); > + if ( !cmp ) > + { > + if ( !valid ) > + rb_erase(&temp->rbnode, &d->arch.vgic.its_devices); > + > + spin_unlock(&d->arch.vgic.its_devices_lock); > + > + if ( valid ) > + return -EBUSY; > + > + return remove_mapped_guest_device(temp); > + } > + > + if ( cmp > 0 ) > + new = &((*new)->rb_left); > + else > + new = &((*new)->rb_right); > + } > + > + if ( !valid ) > + goto out_unlock; > + > + ret = -ENOMEM; > + > + /* An Interrupt Translation Table needs to be 256-byte aligned. */ > + itt_addr = _xzalloc(nr_events * hw_its->itte_size, 256); As I mentioned, in previous version, if itt_addr is not enough size, ITS would overwrite and corrupt memory. Similar to size passed in MAPD cmd, itt_addr should also be allocated of size ROUNDUP(nr_events, LPI_BLOCK). > + if ( !itt_addr ) > + goto out_unlock; > + > + dev = xzalloc(struct its_devices); > + if ( !dev ) > + goto out_unlock; > + > + /* > + * Allocate the pending_irqs for each virtual LPI. They will be put > + * into the domain's radix tree upon the guest's MAPTI command. > + */ > + dev->pend_irqs = xzalloc_array(struct pending_irq, nr_events); > + if ( !dev->pend_irqs ) > + goto out_unlock; > + > + ret = its_send_cmd_mapd(hw_its, host_devid, > + fls(ROUNDUP(nr_events, LPI_BLOCK) - 1) - 1, > + virt_to_maddr(itt_addr), true); > + if ( ret ) > + goto out_unlock; > + > + dev->itt_addr = itt_addr; > + dev->hw_its = hw_its; > + dev->guest_doorbell = guest_doorbell; > + dev->guest_devid = guest_devid; > + dev->host_devid = host_devid; > + dev->eventids = nr_events; > + > + rb_link_node(&dev->rbnode, parent, new); > + rb_insert_color(&dev->rbnode, &d->arch.vgic.its_devices); > + > + spin_unlock(&d->arch.vgic.its_devices_lock); > + > + return 0; > + > +out_unlock: > + spin_unlock(&d->arch.vgic.its_devices_lock); > + if ( dev ) > + { > + xfree(dev->pend_irqs); > + xfree(dev->host_lpi_blocks); > + } > + xfree(itt_addr); > + xfree(dev); > + return ret; > +} > + > +/* Removing any connections a domain had to any ITS in the system. */ > +void gicv3_its_unmap_all_devices(struct domain *d) > +{ > + struct rb_node *victim; > + struct its_devices *dev; > + > + /* > + * This is an easily readable, but suboptimal implementation. > + * It uses the provided iteration wrapper and erases each node, which > + * possibly triggers rebalancing. > + * This seems overkill since we are going to abolish the whole tree, but > + * avoids an open-coded re-implementation of the traversal functions with > + * some recursive function calls. > + */ > +restart: > + spin_lock(&d->arch.vgic.its_devices_lock); > + if ( (victim = rb_first(&d->arch.vgic.its_devices)) ) > + { > + dev = rb_entry(victim, struct its_devices, rbnode); > + rb_erase(victim, &d->arch.vgic.its_devices); > + > + spin_unlock(&d->arch.vgic.its_devices_lock); > + > + remove_mapped_guest_device(dev); > + > + goto restart; > + } > + > + spin_unlock(&d->arch.vgic.its_devices_lock); > +} > + > /* 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) > { > @@ -459,6 +685,7 @@ void gicv3_its_dt_init(const struct dt_device_node *node) > its_data->addr = addr; > its_data->size = size; > its_data->dt_node = its; > + spin_lock_init(&its_data->cmd_lock); > > printk("GICv3: Found ITS @0x%lx\n", addr); > > diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c > index d61479d..6242252 100644 > --- a/xen/arch/arm/vgic-v3.c > +++ b/xen/arch/arm/vgic-v3.c > @@ -1450,6 +1450,9 @@ static int vgic_v3_domain_init(struct domain *d) > d->arch.vgic.nr_regions = rdist_count; > d->arch.vgic.rdist_regions = rdist_regions; > > + spin_lock_init(&d->arch.vgic.its_devices_lock); > + d->arch.vgic.its_devices = RB_ROOT; > + > /* > * Domain 0 gets the hardware address. > * Guests get the virtual platform layout. > @@ -1522,6 +1525,7 @@ static int vgic_v3_domain_init(struct domain *d) > > static void vgic_v3_domain_free(struct domain *d) > { > + gicv3_its_unmap_all_devices(d); > xfree(d->arch.vgic.rdist_regions); > } > > diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h > index 2d6fbb1..e559027 100644 > --- a/xen/include/asm-arm/domain.h > +++ b/xen/include/asm-arm/domain.h > @@ -11,6 +11,7 @@ > #include <asm/gic.h> > #include <public/hvm/params.h> > #include <xen/serial.h> > +#include <xen/rbtree.h> > > struct hvm_domain > { > @@ -109,6 +110,8 @@ struct arch_domain > } *rdist_regions; > int nr_regions; /* Number of rdist regions */ > uint32_t rdist_stride; /* Re-Distributor stride */ > + struct rb_root its_devices; /* Devices mapped to an ITS */ > + spinlock_t its_devices_lock; /* Protects the its_devices tree > */ > #endif > } vgic; > > diff --git a/xen/include/asm-arm/gic_v3_its.h > b/xen/include/asm-arm/gic_v3_its.h > index 4c2ae1c..4ade5f6 100644 > --- a/xen/include/asm-arm/gic_v3_its.h > +++ b/xen/include/asm-arm/gic_v3_its.h > @@ -48,6 +48,10 @@ > #define GITS_TYPER_DEVICE_ID_BITS(r) (((r & GITS_TYPER_DEVIDS_MASK) >> \ > GITS_TYPER_DEVIDS_SHIFT) + 1) > #define GITS_TYPER_IDBITS_SHIFT 8 > +#define GITS_TYPER_ITT_SIZE_SHIFT 4 > +#define GITS_TYPER_ITT_SIZE_MASK (0xfUL << GITS_TYPER_ITT_SIZE_SHIFT) > +#define GITS_TYPER_ITT_SIZE(r) ((((r) & GITS_TYPER_ITT_SIZE_MASK) > >> \ > + GITS_TYPER_ITT_SIZE_SHIFT) + > 1) > > #define GITS_IIDR_VALUE 0x34c > > @@ -94,7 +98,10 @@ > #define GITS_CMD_MOVALL 0x0e > #define GITS_CMD_DISCARD 0x0f > > +#define ITS_DOORBELL_OFFSET 0x10040 > + > #include <xen/device_tree.h> > +#include <xen/rbtree.h> > > #define HOST_ITS_FLUSH_CMD_QUEUE (1U << 0) > #define HOST_ITS_USES_PTA (1U << 1) > @@ -109,6 +116,7 @@ struct host_its { > unsigned int devid_bits; > spinlock_t cmd_lock; > void *cmd_buf; > + unsigned int itte_size; > unsigned int flags; > }; > > @@ -135,6 +143,17 @@ uint64_t gicv3_get_redist_address(unsigned int cpu, bool > use_pta); > /* Map a collection for this host CPU to each host ITS. */ > int gicv3_its_setup_collection(unsigned int cpu); > > +/* > + * Map a device on the host by allocating an ITT on the host (ITS). > + * "nr_event" specifies how many events (interrupts) this device will need. > + * Setting "valid" to false deallocates the device. > + */ > +int gicv3_its_map_guest_device(struct domain *d, > + paddr_t host_doorbell, uint32_t host_devid, > + paddr_t guest_doorbell, uint32_t guest_devid, > + uint32_t nr_events, bool valid); > +void gicv3_its_unmap_all_devices(struct domain *d); > + > #else > > static LIST_HEAD(host_its_list); > @@ -173,6 +192,10 @@ static inline int gicv3_its_setup_collection(unsigned > int cpu) > return 0; > } > > +static inline void gicv3_its_unmap_all_devices(struct domain *d) > +{ > +} > + > #endif /* CONFIG_HAS_ITS */ > > #endif > -- > 2.9.0 > _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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