lkml.org 
[lkml]   [2017]   [Oct]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v6 7/9] KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared
    Date
    When the GITS_BASER<n>.Valid gets cleared, the data structures in
    guest RAM are not valid anymore. The device, collection
    and LPI lists stored in the in-kernel ITS represent the same
    information in some form of cache. So let's void the cache.

    Signed-off-by: Eric Auger <eric.auger@redhat.com>

    ---
    v5 -> v6:
    - rename type into device_type and revert tthe u64 -> int change
    - remove the default clause
    - take the its mutex lock around vgic_its_free_device/collection_list

    v4 -> v5:
    - add comment about locking

    v2 -> v3:
    - add a comment and clear cache in if block
    ---
    virt/kvm/arm/vgic/vgic-its.c | 26 ++++++++++++++++++++++----
    1 file changed, 22 insertions(+), 4 deletions(-)

    diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
    index 5b7be85..2a92d4d 100644
    --- a/virt/kvm/arm/vgic/vgic-its.c
    +++ b/virt/kvm/arm/vgic/vgic-its.c
    @@ -1428,7 +1428,7 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
    unsigned long val)
    {
    const struct vgic_its_abi *abi = vgic_its_get_abi(its);
    - u64 entry_size, device_type;
    + u64 entry_size, table_type;
    u64 reg, *regptr, clearbits = 0;

    /* When GITS_CTLR.Enable is 1, we ignore write accesses. */
    @@ -1439,12 +1439,12 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
    case 0:
    regptr = &its->baser_device_table;
    entry_size = abi->dte_esz;
    - device_type = GITS_BASER_TYPE_DEVICE;
    + table_type = GITS_BASER_TYPE_DEVICE;
    break;
    case 1:
    regptr = &its->baser_coll_table;
    entry_size = abi->cte_esz;
    - device_type = GITS_BASER_TYPE_COLLECTION;
    + table_type = GITS_BASER_TYPE_COLLECTION;
    clearbits = GITS_BASER_INDIRECT;
    break;
    default:
    @@ -1456,10 +1456,28 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
    reg &= ~clearbits;

    reg |= (entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT;
    - reg |= device_type << GITS_BASER_TYPE_SHIFT;
    + reg |= table_type << GITS_BASER_TYPE_SHIFT;
    reg = vgic_sanitise_its_baser(reg);

    *regptr = reg;
    +
    + /*
    + * If the table is no longer valid, we clear the associated cached data.
    + * Note: there cannot be any race with save/restore code which locks
    + * all vcpus.
    + */
    + if (!(reg & GITS_BASER_VALID)) {
    + mutex_lock(&its->its_lock);
    + switch (table_type) {
    + case GITS_BASER_TYPE_DEVICE:
    + vgic_its_free_device_list(kvm, its);
    + break;
    + case GITS_BASER_TYPE_COLLECTION:
    + vgic_its_free_collection_list(kvm, its);
    + break;
    + }
    + mutex_unlock(&its->its_lock);
    + }
    }

    static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu,
    --
    2.5.5
    \
     
     \ /
      Last update: 2017-10-26 17:26    [W:3.713 / U:0.376 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site