From ab01c6bdacc43c41c6b326889f4358f5afc38bf9 Mon Sep 17 00:00:00 2001 From: Eric Auger Date: Thu, 23 Mar 2017 15:14:00 +0100 Subject: [PATCH] KVM: arm64: vgic-its: Implement vgic_mmio_uaccess_write_its_iidr The GITS_IIDR revision field is used to encode the migration ABI revision. So we need to restore it to check the table layout is readable by the destination. By writing the IIDR, userspace thus forces the ABI revision to be used and this must be less than or equal to the max revision KVM supports. Signed-off-by: Eric Auger Reviewed-by: Christoffer Dall --- include/linux/irqchip/arm-gic-v3.h | 5 +++++ virt/kvm/arm/vgic/vgic-its.c | 23 ++++++++++++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index 81ebe43..2eaea30 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -242,6 +242,11 @@ #define GITS_TYPER_PTA (1UL << 19) #define GITS_TYPER_HWCOLLCNT_SHIFT 24 +#define GITS_IIDR_REV_SHIFT 12 +#define GITS_IIDR_REV_MASK (0xf << GITS_IIDR_REV_SHIFT) +#define GITS_IIDR_REV(r) (((r) >> GITS_IIDR_REV_SHIFT) & 0xf) +#define GITS_IIDR_PRODUCTID_SHIFT 24 + #define GITS_CBASER_VALID (1ULL << 63) #define GITS_CBASER_SHAREABILITY_SHIFT (10) #define GITS_CBASER_INNER_CACHEABILITY_SHIFT (59) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 4f6ea46..9338efb 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -434,7 +434,23 @@ static unsigned long vgic_mmio_read_its_iidr(struct kvm *kvm, struct vgic_its *its, gpa_t addr, unsigned int len) { - return (PRODUCT_ID_KVM << 24) | (IMPLEMENTER_ARM << 0); + u32 val; + + val = (its->abi_rev << GITS_IIDR_REV_SHIFT) & GITS_IIDR_REV_MASK; + val |= (PRODUCT_ID_KVM << GITS_IIDR_PRODUCTID_SHIFT) | IMPLEMENTER_ARM; + return val; +} + +static int vgic_mmio_uaccess_write_its_iidr(struct kvm *kvm, + struct vgic_its *its, + gpa_t addr, unsigned int len, + unsigned long val) +{ + u32 rev = GITS_IIDR_REV(val); + + if (rev >= NR_ITS_ABIS) + return -EINVAL; + return vgic_its_set_abi(its, rev); } static unsigned long vgic_mmio_read_its_idregs(struct kvm *kvm, @@ -1415,8 +1431,9 @@ static struct vgic_register_region its_registers[] = { REGISTER_ITS_DESC(GITS_CTLR, vgic_mmio_read_its_ctlr, vgic_mmio_write_its_ctlr, 4, VGIC_ACCESS_32bit), - REGISTER_ITS_DESC(GITS_IIDR, - vgic_mmio_read_its_iidr, its_mmio_write_wi, 4, + REGISTER_ITS_DESC_UACCESS(GITS_IIDR, + vgic_mmio_read_its_iidr, its_mmio_write_wi, + vgic_mmio_uaccess_write_its_iidr, 4, VGIC_ACCESS_32bit), REGISTER_ITS_DESC(GITS_TYPER, vgic_mmio_read_its_typer, its_mmio_write_wi, 8, -- 2.7.4