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| author | Marc Zyngier <maz@kernel.org> | 2022-04-05 21:23:27 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2022-05-04 16:09:53 +0300 |
| commit | 49a1a2c70a7fd820fe60a65a3e38ab9095082dc9 (patch) | |
| tree | d9d3e7cf5b54c8c3fd49faca4bfd646a0b036a4b /arch/arm64/kvm/vgic/vgic-mmio-v2.c | |
| parent | 4645d11f4a5538ec1221f36e397cfb0115718ffe (diff) | |
| download | linux-49a1a2c70a7fd820fe60a65a3e38ab9095082dc9.tar.xz | |
KVM: arm64: vgic-v3: Advertise GICR_CTLR.{IR, CES} as a new GICD_IIDR revision
Since adversising GICR_CTLR.{IC,CES} is directly observable from
a guest, we need to make it selectable from userspace.
For that, bump the default GICD_IIDR revision and let userspace
downgrade it to the previous default. For GICv2, the two distributor
revisions are strictly equivalent.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220405182327.205520-5-maz@kernel.org
Diffstat (limited to 'arch/arm64/kvm/vgic/vgic-mmio-v2.c')
| -rw-r--r-- | arch/arm64/kvm/vgic/vgic-mmio-v2.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/arch/arm64/kvm/vgic/vgic-mmio-v2.c b/arch/arm64/kvm/vgic/vgic-mmio-v2.c index 12e4c223e6b8..77a67e9d3d14 100644 --- a/arch/arm64/kvm/vgic/vgic-mmio-v2.c +++ b/arch/arm64/kvm/vgic/vgic-mmio-v2.c @@ -73,9 +73,13 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len, unsigned long val) { + struct vgic_dist *dist = &vcpu->kvm->arch.vgic; + u32 reg; + switch (addr & 0x0c) { case GIC_DIST_IIDR: - if (val != vgic_mmio_read_v2_misc(vcpu, addr, len)) + reg = vgic_mmio_read_v2_misc(vcpu, addr, len); + if ((reg ^ val) & ~GICD_IIDR_REVISION_MASK) return -EINVAL; /* @@ -87,8 +91,16 @@ static int vgic_mmio_uaccess_write_v2_misc(struct kvm_vcpu *vcpu, * migration from old kernels to new kernels with legacy * userspace. */ - vcpu->kvm->arch.vgic.v2_groups_user_writable = true; - return 0; + reg = FIELD_GET(GICD_IIDR_REVISION_MASK, reg); + switch (reg) { + case KVM_VGIC_IMP_REV_2: + case KVM_VGIC_IMP_REV_3: + vcpu->kvm->arch.vgic.v2_groups_user_writable = true; + dist->implementation_rev = reg; + return 0; + default: + return -EINVAL; + } } vgic_mmio_write_v2_misc(vcpu, addr, len, val); |