When accessing HW via the gdbstub we can't easily figure out what the cpu_index is. The canonical case is current_cpu but for some cases that will be NULL. For debug accesses we can overload requester_id and make the GIC a bit smarter about fishing that out.
[AJB: very much a PoC hack for now but interested if this makes sense. We could encode cpu_index in another field but that would grow MxTxAttrs even more.] Signed-off-by: Alex Bennée <alex.ben...@linaro.org> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/124 --- include/exec/memattrs.h | 2 +- hw/core/cpu-sysemu.c | 15 +++++++++++---- hw/intc/arm_gic.c | 33 +++++++++++++++++++-------------- 3 files changed, 31 insertions(+), 19 deletions(-) diff --git a/include/exec/memattrs.h b/include/exec/memattrs.h index 9fb98bc1ef..1333a34cb3 100644 --- a/include/exec/memattrs.h +++ b/include/exec/memattrs.h @@ -43,7 +43,7 @@ typedef struct MemTxAttrs { * (see MEMTX_ACCESS_ERROR). */ unsigned int memory:1; - /* Requester ID (for MSI for example) */ + /* Requester ID (for MSI for example) or cpu_index for debug */ unsigned int requester_id:16; /* Invert endianness for this page */ unsigned int byte_swap:1; diff --git a/hw/core/cpu-sysemu.c b/hw/core/cpu-sysemu.c index 00253f8929..77f0b1a289 100644 --- a/hw/core/cpu-sysemu.c +++ b/hw/core/cpu-sysemu.c @@ -51,13 +51,20 @@ hwaddr cpu_get_phys_page_attrs_debug(CPUState *cpu, vaddr addr, MemTxAttrs *attrs) { CPUClass *cc = CPU_GET_CLASS(cpu); + MemTxAttrs local = { }; + hwaddr res; if (cc->sysemu_ops->get_phys_page_attrs_debug) { - return cc->sysemu_ops->get_phys_page_attrs_debug(cpu, addr, attrs); + res = cc->sysemu_ops->get_phys_page_attrs_debug(cpu, addr, &local); + } else { + /* Fallback for CPUs which don't implement the _attrs_ hook */ + local = MEMTXATTRS_UNSPECIFIED; + res = cc->sysemu_ops->get_phys_page_debug(cpu, addr); } - /* Fallback for CPUs which don't implement the _attrs_ hook */ - *attrs = MEMTXATTRS_UNSPECIFIED; - return cc->sysemu_ops->get_phys_page_debug(cpu, addr); + + local.requester_id = cpu->cpu_index; + *attrs = local; + return res; } hwaddr cpu_get_phys_page_debug(CPUState *cpu, vaddr addr) diff --git a/hw/intc/arm_gic.c b/hw/intc/arm_gic.c index 492b2421ab..6a007a7f9e 100644 --- a/hw/intc/arm_gic.c +++ b/hw/intc/arm_gic.c @@ -56,17 +56,22 @@ static const uint8_t gic_id_gicv2[] = { 0x04, 0x00, 0x00, 0x00, 0x90, 0xb4, 0x2b, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; -static inline int gic_get_current_cpu(GICState *s) +static inline int gic_get_current_cpu(GICState *s, MemTxAttrs attrs) { if (!qtest_enabled() && s->num_cpu > 1) { - return current_cpu->cpu_index; + if (current_cpu) { + return current_cpu->cpu_index; + } else { + /* worst case this will be zeroed */ + return attrs.requester_id; + } } return 0; } -static inline int gic_get_current_vcpu(GICState *s) +static inline int gic_get_current_vcpu(GICState *s, MemTxAttrs attrs) { - return gic_get_current_cpu(s) + GIC_NCPU; + return gic_get_current_cpu(s, attrs) + GIC_NCPU; } /* Return true if this GIC config has interrupt groups, which is @@ -951,7 +956,7 @@ static uint32_t gic_dist_readb(void *opaque, hwaddr offset, MemTxAttrs attrs) int cm; int mask; - cpu = gic_get_current_cpu(s); + cpu = gic_get_current_cpu(s, attrs); cm = 1 << cpu; if (offset < 0x100) { if (offset == 0) { /* GICD_CTLR */ @@ -1182,7 +1187,7 @@ static void gic_dist_writeb(void *opaque, hwaddr offset, int i; int cpu; - cpu = gic_get_current_cpu(s); + cpu = gic_get_current_cpu(s, attrs); if (offset < 0x100) { if (offset == 0) { if (s->security_extn && !attrs.secure) { @@ -1476,7 +1481,7 @@ static void gic_dist_writel(void *opaque, hwaddr offset, int mask; int target_cpu; - cpu = gic_get_current_cpu(s); + cpu = gic_get_current_cpu(s, attrs); irq = value & 0xf; switch ((value >> 24) & 3) { case 0: @@ -1780,7 +1785,7 @@ static MemTxResult gic_thiscpu_read(void *opaque, hwaddr addr, uint64_t *data, unsigned size, MemTxAttrs attrs) { GICState *s = (GICState *)opaque; - return gic_cpu_read(s, gic_get_current_cpu(s), addr, data, attrs); + return gic_cpu_read(s, gic_get_current_cpu(s, attrs), addr, data, attrs); } static MemTxResult gic_thiscpu_write(void *opaque, hwaddr addr, @@ -1788,7 +1793,7 @@ static MemTxResult gic_thiscpu_write(void *opaque, hwaddr addr, MemTxAttrs attrs) { GICState *s = (GICState *)opaque; - return gic_cpu_write(s, gic_get_current_cpu(s), addr, value, attrs); + return gic_cpu_write(s, gic_get_current_cpu(s, attrs), addr, value, attrs); } /* Wrappers to read/write the GIC CPU interface for a specific CPU. @@ -1818,7 +1823,7 @@ static MemTxResult gic_thisvcpu_read(void *opaque, hwaddr addr, uint64_t *data, { GICState *s = (GICState *)opaque; - return gic_cpu_read(s, gic_get_current_vcpu(s), addr, data, attrs); + return gic_cpu_read(s, gic_get_current_vcpu(s, attrs), addr, data, attrs); } static MemTxResult gic_thisvcpu_write(void *opaque, hwaddr addr, @@ -1827,7 +1832,7 @@ static MemTxResult gic_thisvcpu_write(void *opaque, hwaddr addr, { GICState *s = (GICState *)opaque; - return gic_cpu_write(s, gic_get_current_vcpu(s), addr, value, attrs); + return gic_cpu_write(s, gic_get_current_vcpu(s, attrs), addr, value, attrs); } static uint32_t gic_compute_eisr(GICState *s, int cpu, int lr_start) @@ -1860,7 +1865,7 @@ static uint32_t gic_compute_elrsr(GICState *s, int cpu, int lr_start) static void gic_vmcr_write(GICState *s, uint32_t value, MemTxAttrs attrs) { - int vcpu = gic_get_current_vcpu(s); + int vcpu = gic_get_current_vcpu(s, attrs); uint32_t ctlr; uint32_t abpr; uint32_t bpr; @@ -1995,7 +2000,7 @@ static MemTxResult gic_thiscpu_hyp_read(void *opaque, hwaddr addr, uint64_t *dat { GICState *s = (GICState *)opaque; - return gic_hyp_read(s, gic_get_current_cpu(s), addr, data, attrs); + return gic_hyp_read(s, gic_get_current_cpu(s, attrs), addr, data, attrs); } static MemTxResult gic_thiscpu_hyp_write(void *opaque, hwaddr addr, @@ -2004,7 +2009,7 @@ static MemTxResult gic_thiscpu_hyp_write(void *opaque, hwaddr addr, { GICState *s = (GICState *)opaque; - return gic_hyp_write(s, gic_get_current_cpu(s), addr, value, attrs); + return gic_hyp_write(s, gic_get_current_cpu(s, attrs), addr, value, attrs); } static MemTxResult gic_do_hyp_read(void *opaque, hwaddr addr, uint64_t *data, -- 2.30.2
