[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC 2/2] xen/arm: vgic-v3: Support 32-bit access for 64-bit registers
Based on 8.1.3 (IHI 0069A), unless stated otherwise, the 64-bit registers supports both 32-bit and 64-bits access. All the registers we properly emulate (i.e not RAZ/WI) supports 32-bit access. For RAZ/WI, it's also seems to be the case but I'm not 100% sure. Anyway, emulating 32-bit access for them doesn't hurt. Note that we would need some extra care when they will be implemented (for instance GICR_PROPBASER). Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx> --- This is technically fixing boot of FreeBSD ARM64 guest with GICv3. AFAICT, Linux is not using 32-bit access in the GICv3 code expect for the ITS (which we don't support yet). So this patch is a good candidate for Xen 4.6, maybe only via backporting (i.e Xen 4.6.1) given that none of our supports guests OS needs them right now. --- xen/arch/arm/vgic-v3.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c index 7ef7b16..0ef5d42 100644 --- a/xen/arch/arm/vgic-v3.c +++ b/xen/arch/arm/vgic-v3.c @@ -103,6 +103,15 @@ static struct vcpu *vgic_v3_get_target_vcpu(struct vcpu *v, unsigned int irq) return v_target; } +static inline bool vgic_reg64_check_access(struct hsr_dabt dabt) +{ + /* + * 64 bits registers can be accessible using 32-bit and 64-bit unless + * stated otherwise (See 8.1.3 ARM IHI 0069A). + */ + return ( dabt.size == DABT_DOUBLE_WORD || dabt.size == DABT_WORD ); +} + static int __vgic_v3_rdistr_rd_mmio_read(struct vcpu *v, mmio_info_t *info, uint32_t gicr_reg) { @@ -123,7 +132,7 @@ static int __vgic_v3_rdistr_rd_mmio_read(struct vcpu *v, mmio_info_t *info, { uint64_t typer, aff; - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( !vgic_reg64_check_access(dabt) ) goto bad_width; /* TBD: Update processor id in [23:8] when ITS support is added */ aff = (MPIDR_AFFINITY_LEVEL(v->arch.vmpidr, 3) << 56 | MPIDR_AFFINITY_LEVEL(v->arch.vmpidr, 2) << 48 | @@ -209,7 +218,7 @@ bad_width: return 0; read_as_zero_64: - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( !vgic_reg64_check_access(dabt) ) goto bad_width; *r = 0; return 1; @@ -286,7 +295,7 @@ bad_width: return 0; write_ignore_64: - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( vgic_reg64_check_access(dabt) ) goto bad_width; return 1; write_ignore_32: @@ -774,7 +783,7 @@ static int vgic_v3_distr_mmio_read(struct vcpu *v, mmio_info_t *info) { uint64_t irouter; - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( !vgic_reg64_check_access(dabt) ) goto bad_width; rank = vgic_rank_offset(v, 64, gicd_reg - GICD_IROUTER, DABT_DOUBLE_WORD); if ( rank == NULL ) goto read_as_zero; @@ -850,7 +859,7 @@ bad_width: return 0; read_as_zero_64: - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( vgic_reg64_check_access(dabt) ) goto bad_width; *r = 0; return 1; @@ -935,7 +944,7 @@ static int vgic_v3_distr_mmio_write(struct vcpu *v, mmio_info_t *info) /* SGI/PPI is RES0 */ goto write_ignore_64; case GICD_IROUTER32 ... GICD_IROUTERN: - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( !vgic_reg64_check_access(dabt) ) goto bad_width; rank = vgic_rank_offset(v, 64, gicd_reg - GICD_IROUTER, DABT_DOUBLE_WORD); if ( rank == NULL ) goto write_ignore; @@ -1016,7 +1025,7 @@ write_ignore_32: return 1; write_ignore_64: - if ( dabt.size != DABT_DOUBLE_WORD ) goto bad_width; + if ( vgic_reg64_check_access(dabt) ) goto bad_width; return 1; write_ignore: -- 2.1.4 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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