diff options
author | Eric Auger <eric.auger@redhat.com> | 2021-04-05 19:39:40 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2021-04-06 16:51:38 +0300 |
commit | 28e9d4bce3be9b8fec6c854f87923db99c8fb874 (patch) | |
tree | 78ebce0a0c541f16786c52ce58e4f47ca8e57281 | |
parent | e5a35635464bc5304674b84ea42615a3fd0bd949 (diff) | |
download | linux-28e9d4bce3be9b8fec6c854f87923db99c8fb874.tar.xz |
KVM: arm64: vgic-v3: Expose GICR_TYPER.Last for userspace
Commit 23bde34771f1 ("KVM: arm64: vgic-v3: Drop the
reporting of GICR_TYPER.Last for userspace") temporarily fixed
a bug identified when attempting to access the GICR_TYPER
register before the redistributor region setting, but dropped
the support of the LAST bit.
Emulating the GICR_TYPER.Last bit still makes sense for
architecture compliance though. This patch restores its support
(if the redistributor region was set) while keeping the code safe.
We introduce a new helper, vgic_mmio_vcpu_rdist_is_last() which
computes whether a redistributor is the highest one of a series
of redistributor contributor pages.
With this new implementation we do not need to have a uaccess
read accessor anymore.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210405163941.510258-9-eric.auger@redhat.com
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-mmio-v3.c | 46 | ||||
-rw-r--r-- | include/kvm/arm_vgic.h | 1 |
2 files changed, 28 insertions, 19 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v3.c b/arch/arm64/kvm/vgic/vgic-mmio-v3.c index e1ed0c5a8eaa..03a253785700 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v3.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v3.c @@ -251,30 +251,35 @@ static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu, vgic_enable_lpis(vcpu); } -static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu, - gpa_t addr, unsigned int len) +static bool vgic_mmio_vcpu_rdist_is_last(struct kvm_vcpu *vcpu) { - unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu); + struct vgic_dist *vgic = &vcpu->kvm->arch.vgic; struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; - struct vgic_redist_region *rdreg = vgic_cpu->rdreg; - int target_vcpu_id = vcpu->vcpu_id; - gpa_t last_rdist_typer = rdreg->base + GICR_TYPER + - (rdreg->free_index - 1) * KVM_VGIC_V3_REDIST_SIZE; - u64 value; + struct vgic_redist_region *iter, *rdreg = vgic_cpu->rdreg; - value = (u64)(mpidr & GENMASK(23, 0)) << 32; - value |= ((target_vcpu_id & 0xffff) << 8); + if (!rdreg) + return false; - if (addr == last_rdist_typer) - value |= GICR_TYPER_LAST; - if (vgic_has_its(vcpu->kvm)) - value |= GICR_TYPER_PLPIS; + if (vgic_cpu->rdreg_index < rdreg->free_index - 1) { + return false; + } else if (rdreg->count && vgic_cpu->rdreg_index == (rdreg->count - 1)) { + struct list_head *rd_regions = &vgic->rd_regions; + gpa_t end = rdreg->base + rdreg->count * KVM_VGIC_V3_REDIST_SIZE; - return extract_bytes(value, addr & 7, len); + /* + * the rdist is the last one of the redist region, + * check whether there is no other contiguous rdist region + */ + list_for_each_entry(iter, rd_regions, list) { + if (iter->base == end && iter->free_index > 0) + return false; + } + } + return true; } -static unsigned long vgic_uaccess_read_v3r_typer(struct kvm_vcpu *vcpu, - gpa_t addr, unsigned int len) +static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu, + gpa_t addr, unsigned int len) { unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu); int target_vcpu_id = vcpu->vcpu_id; @@ -286,7 +291,9 @@ static unsigned long vgic_uaccess_read_v3r_typer(struct kvm_vcpu *vcpu, if (vgic_has_its(vcpu->kvm)) value |= GICR_TYPER_PLPIS; - /* reporting of the Last bit is not supported for userspace */ + if (vgic_mmio_vcpu_rdist_is_last(vcpu)) + value |= GICR_TYPER_LAST; + return extract_bytes(value, addr & 7, len); } @@ -612,7 +619,7 @@ static const struct vgic_register_region vgic_v3_rd_registers[] = { VGIC_ACCESS_32bit), REGISTER_DESC_WITH_LENGTH_UACCESS(GICR_TYPER, vgic_mmio_read_v3r_typer, vgic_mmio_write_wi, - vgic_uaccess_read_v3r_typer, vgic_mmio_uaccess_write_wi, 8, + NULL, vgic_mmio_uaccess_write_wi, 8, VGIC_ACCESS_64bit | VGIC_ACCESS_32bit), REGISTER_DESC_WITH_LENGTH(GICR_WAKER, vgic_mmio_read_raz, vgic_mmio_write_wi, 4, @@ -714,6 +721,7 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu) return -EINVAL; vgic_cpu->rdreg = rdreg; + vgic_cpu->rdreg_index = rdreg->free_index; rd_base = rdreg->base + rdreg->free_index * KVM_VGIC_V3_REDIST_SIZE; diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 3d74f1060bd1..ec621180ef09 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -322,6 +322,7 @@ struct vgic_cpu { */ struct vgic_io_device rd_iodev; struct vgic_redist_region *rdreg; + u32 rdreg_index; /* Contains the attributes and gpa of the LPI pending tables. */ u64 pendbaser; |