|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [RFC PATCH v2 06/26] ARM: GICv3 ITS: introduce device mapping
On Thu, 22 Dec 2016, Andre Przywara 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 a list 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-its.c | 118
> ++++++++++++++++++++++++++++++++++++++++++
> xen/arch/arm/vgic.c | 3 ++
> xen/include/asm-arm/domain.h | 2 +
> xen/include/asm-arm/gic-its.h | 22 ++++++++
> 4 files changed, 145 insertions(+)
>
> diff --git a/xen/arch/arm/gic-its.c b/xen/arch/arm/gic-its.c
> index d0f5fd1..e157c6b 100644
> --- a/xen/arch/arm/gic-its.c
> +++ b/xen/arch/arm/gic-its.c
> @@ -21,6 +21,7 @@
> #include <xen/err.h>
> #include <xen/device_tree.h>
> #include <xen/libfdt/libfdt.h>
> +#include <xen/sched.h>
> #include <xen/sizes.h>
> #include <asm/p2m.h>
> #include <asm/io.h>
> @@ -108,6 +109,21 @@ static int its_send_cmd_mapc(struct host_its *its, int
> collection_id, int cpu)
> return its_send_command(its, cmd);
> }
>
> +static int its_send_cmd_mapd(struct host_its *its, uint32_t deviceid,
> + int size, uint64_t itt_addr, bool valid)
> +{
> + uint64_t cmd[4];
> +
> + cmd[0] = GITS_CMD_MAPD | ((uint64_t)deviceid << 32);
> + cmd[1] = size & GENMASK(4, 0);
> + cmd[2] = itt_addr & GENMASK(51, 8);
> + if ( valid )
> + cmd[2] |= BIT_ULL(63);
> + cmd[3] = 0x00;
> +
> + return its_send_command(its, cmd);
> +}
> +
> /* Set up the (1:1) collection mapping for the given host CPU. */
> void gicv3_its_setup_collection(int cpu)
> {
> @@ -237,6 +253,7 @@ int gicv3_its_init(struct host_its *hw_its)
>
> reg = readq_relaxed(hw_its->its_base + GITS_TYPER);
> hw_its->pta = !!(reg & GITS_TYPER_PTA);
> + hw_its->itte_size = ((reg >> 4) & 0xf) + 1;
Please #define all numbers
> for ( i = 0; i < GITS_BASER_NR_REGS; i++ )
> {
> @@ -358,6 +375,107 @@ int gicv3_lpi_init_host_lpis(unsigned int hw_lpi_bits)
> return 0;
> }
>
> +static void remove_mapped_guest_device(struct its_devices *dev)
> +{
> + if ( dev->hw_its )
> + its_send_cmd_mapd(dev->hw_its, dev->host_devid, 0, 0, false);
> +
> + xfree(dev->itt_addr);
> + xfree(dev);
> +}
> +
> +int gicv3_its_map_device(struct domain *d, int host_devid, int guest_devid,
> + int bits, bool valid)
> +{
> + void *itt_addr = NULL;
> + struct its_devices *dev, *temp;
> + struct host_its *hw_its;
> + int ret;
> +
> + /* check for already existing mappings */
> + spin_lock(&d->arch.vgic.its_devices_lock);
> + list_for_each_entry_safe(dev, temp, &d->arch.vgic.its_devices, entry)
> + {
> + if ( dev->guest_devid != guest_devid )
> + continue;
> +
> + if ( !valid )
> + list_del(&dev->entry);
> +
> + spin_unlock(&d->arch.vgic.its_devices_lock);
> +
> + if ( valid )
> + return -EBUSY;
> +
> + remove_mapped_guest_device(dev);
> +
> + return 0;
> + }
> + spin_unlock(&d->arch.vgic.its_devices_lock);
Compared to the previous version, now the list is per-domain, which is
better for DomUs, but not for Dom0. In the case of Dom0 the number of
iterations will be the same.
I suggest we move to a different data structure, such as an hashtable or
an rbtree. If devids were guaranteed to be dense, then we could store
struct its_devices pointers in an array and direct access them, but I
don't think they are?
If devids are sparse, using a per-domain structure could be a good idea,
but we still need to prevent a device from being assigned to two domains
simultaneously. Is there a check to avoid that?
> + if ( !valid )
> + return -ENOENT;
> +
> + /* TODO: Work out the correct hardware ITS to use here.
> + * Maybe a per-platform function: devid -> ITS?
> + * Or parsing the DT to find the msi_parent?
> + * Or get Dom0 to give us this information?
> + * For now just use the first ITS.
> + */
> + hw_its = list_first_entry(&host_its_list, struct host_its, entry);
> +
> + itt_addr = _xmalloc(BIT(bits) * hw_its->itte_size, 256);
> + if ( !itt_addr )
> + return -ENOMEM;
> +
> + dev = xmalloc(struct its_devices);
> + if ( !dev )
> + {
> + xfree(itt_addr);
> + return -ENOMEM;
> + }
> +
> + ret = its_send_cmd_mapd(hw_its, host_devid, bits - 1,
> + virt_to_maddr(itt_addr), true);
> + if (ret) {
> + xfree(itt_addr);
> + xfree(dev);
> + return ret;
> + }
> +
> + dev->itt_addr = itt_addr;
> + dev->hw_its = hw_its;
> + dev->guest_devid = guest_devid;
> + dev->host_devid = host_devid;
> + dev->eventids = BIT(bits);
> +
> + spin_lock(&d->arch.vgic.its_devices_lock);
> + list_add_tail(&dev->entry, &d->arch.vgic.its_devices);
> + spin_unlock(&d->arch.vgic.its_devices_lock);
> +
> + return 0;
> +}
> +
> +/* Removing any connections a domain had to any ITS in the system. */
> +int its_remove_domain(struct domain *d)
> +{
> + struct its_devices *dev, *temp;
> +
> +retry:
> +
> + spin_lock(&d->arch.vgic.its_devices_lock);
> + list_for_each_entry_safe(dev, temp, &d->arch.vgic.its_devices, entry)
> + {
> + list_del(&dev->entry);
> + spin_unlock(&d->arch.vgic.its_devices_lock);
> +
> + remove_mapped_guest_device(dev);
> + goto retry;
> + }
> +
> + return 0;
> +}
> +
> /* 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/vgic.c b/xen/arch/arm/vgic.c
> index 364d5f0..de77aaa 100644
> --- a/xen/arch/arm/vgic.c
> +++ b/xen/arch/arm/vgic.c
> @@ -156,6 +156,9 @@ int domain_vgic_init(struct domain *d, unsigned int
> nr_spis)
> for ( i = 0; i < NR_GIC_SGI; i++ )
> set_bit(i, d->arch.vgic.allocated_irqs);
>
> + spin_lock_init(&d->arch.vgic.its_devices_lock);
> + INIT_LIST_HEAD(&d->arch.vgic.its_devices);
> +
> return 0;
> }
>
> diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
> index 2d6fbb1..8ccc32a 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 */
> + struct list_head its_devices; /* devices mapped to an ITS */
> + spinlock_t its_devices_lock; /* protects the its_devices list
> */
> #endif
> } vgic;
>
> diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
> index 68e5f63..525a29d 100644
> --- a/xen/include/asm-arm/gic-its.h
> +++ b/xen/include/asm-arm/gic-its.h
> @@ -93,9 +93,19 @@ struct host_its {
> void __iomem *its_base;
> spinlock_t cmd_lock;
> void *cmd_buf;
> + int itte_size;
> bool pta;
> };
>
> +struct its_devices {
> + struct list_head entry;
> + struct host_its *hw_its;
> + void *itt_addr;
> + uint32_t guest_devid;
> + uint32_t host_devid;
> + uint32_t eventids;
> +};
> +
> extern struct list_head host_its_list;
>
> #ifdef CONFIG_HAS_ITS
> @@ -119,6 +129,13 @@ void gicv3_set_redist_addr(paddr_t address, int
> redist_id);
> /* Map a collection for this host CPU to each host ITS. */
> void gicv3_its_setup_collection(int cpu);
>
> +/* Map a device on the host by allocating an ITT on the host (ITS).
> + * "bits" specifies how many events (interrupts) this device will need.
> + * Setting "valid" to false deallocates the device.
> + */
> +int gicv3_its_map_device(struct domain *d, int host_devid, int guest_devid,
> + int bits, bool valid);
> +
> #else
>
> static inline void gicv3_its_dt_init(const struct dt_device_node *node)
> @@ -146,6 +163,11 @@ static inline void gicv3_set_redist_addr(paddr_t
> address, int redist_id)
> static inline void gicv3_its_setup_collection(int cpu)
> {
> }
> +static inline int gicv3_its_map_device(struct domain *d, int host_devid,
> + int guest_devid, int bits, bool valid)
> +{
> + return -ENODEV;
> +}
>
> #endif /* CONFIG_HAS_ITS */
>
> --
> 2.9.0
>
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |