From 36d6961c2b481614e8d37495896436d9322df052 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 26 Oct 2017 17:23:09 +0200 Subject: KVM: arm/arm64: vgic-its: Free caches when GITS_BASER Valid bit is cleared When the GITS_BASER.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. Reviewed-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Eric Auger Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic-its.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'virt') diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index d46256c07ba5..1732e08a4375 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -1431,7 +1431,7 @@ 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. */ @@ -1442,12 +1442,12 @@ 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: @@ -1459,10 +1459,24 @@ 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 (!(reg & GITS_BASER_VALID)) { + /* Take the its_lock to prevent a race with a save/restore */ + 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, -- cgit