xen/arm: vgic: Drop iactive, ipend, pendsgi field

The current VGIC code doesn't support to change the pending and active status
of an IRQ via the (re-)distributor.

Futhermore, all the access size wasn't support correctly and some
registers was implemented as write-ignore. The latter make very
difficult for a kernel developer to find that we don't support R/W to
those registers.

Make the support consistent:
    - read will return 0 (RAZ)
    - write will print an error and inject a data abort to the guest

Also, those fields was never set and field such as ipend and pendsgi was
doing the same jobs.

Rather than wasting memory, we should better drop it. We could re-introduce
them if we need it when the support will be made.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
[ ijc -- s/XENLOG_ERR/XENLOG_G_ERR/g ]

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 1f52aebda323f7883accea0808ca4788ba9945fb..6d14f83dc1a0172a4653cdbf0bc956a9ff956c4a 100644 (file)
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -94,41 +94,15 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         vgic_unlock_rank(v, rank, flags);
         return 1;
 
+    /* Read the pending status of an IRQ via GICD is not supported */
     case GICD_ISPENDR ... GICD_ISPENDRN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ISPENDR, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->ipend, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
-
     case GICD_ICPENDR ... GICD_ICPENDRN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 0, gicd_reg - GICD_ICPENDR, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->ipend, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
 
+    /* Read the active status of an IRQ via GICD is not supported */
     case GICD_ISACTIVER ... GICD_ISACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ISACTIVER, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->iactive;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
-
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ICACTIVER, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->iactive;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
 
     case GICD_ITARGETSR ... GICD_ITARGETSRN:
         if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
@@ -174,23 +148,10 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         *r = 0xdeadbeef;
         return 1;
 
+    /* Setting/Clearing the SGI pending bit via GICD is not supported */
     case GICD_CPENDSGIR ... GICD_CPENDSGIRN:
-        if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_CPENDSGIR, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->pendsgi, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
-
     case GICD_SPENDSGIR ... GICD_SPENDSGIRN:
-        if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_SPENDSGIR, DABT_WORD);
-        if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->pendsgi, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
 
     /* Implementation defined -- read as zero */
     case 0xfd0 ... 0xfe4:
@@ -349,21 +310,17 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
 
     case GICD_ISACTIVER ... GICD_ISACTIVERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ISACTIVER, DABT_WORD);
-        if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: vGICD: unhandled word write %#"PRIregister" to ISACTIVER%d\n",
+               v, *r, gicd_reg - GICD_ISACTIVER);
+        return 0;
 
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ICACTIVER, DABT_WORD);
-        if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: vGICD: unhandled word write %#"PRIregister" to ICACTIVER%d\n",
+               v, *r, gicd_reg - GICD_ICACTIVER);
+        return 0;
 
     case GICD_ITARGETSR ... GICD_ITARGETSR + 7:
         /* SGI/PPI target is read only */

diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index 609e3c820eed77ebdac03b1990d5299131b9ed6f..c72eb6c3e3cfa5ce8f26ab3d4a1d9b646f5479b4 100644 (file)
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -306,38 +306,16 @@ static int __vgic_v3_distr_common_mmio_read(const char *name, struct vcpu *v,
         *r = rank->ienable;
         vgic_unlock_rank(v, rank, flags);
         return 1;
+    /* Read the pending status of an IRQ via GICD/GICR is not supported */
     case GICD_ISPENDR ... GICD_ISPENDRN:
-        if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ISPENDR, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->ipend, dabt.sign, reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
     case GICD_ICPENDR ... GICD_ICPENDRN:
-        if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ICPENDR, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = vgic_byte_read(rank->ipend, dabt.sign, reg);
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
+
+    /* Read the active status of an IRQ via GICD/GICR is not supported */
     case GICD_ISACTIVER ... GICD_ISACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ISACTIVER, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->iactive;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ICACTIVER, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->iactive;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
+
     case GICD_IPRIORITYR ... GICD_IPRIORITYRN:
         if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 8, reg - GICD_IPRIORITYR, DABT_WORD);
@@ -415,36 +393,32 @@ static int __vgic_v3_distr_common_mmio_write(const char *name, struct vcpu *v,
         return 1;
     case GICD_ISPENDR ... GICD_ISPENDRN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ISPENDR, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->ipend = *r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: %s: unhandled word write %#"PRIregister" to ISPENDR%d\n",
+               v, name, *r, reg - GICD_ISPENDR);
+        return 0;
+
     case GICD_ICPENDR ... GICD_ICPENDRN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ICPENDR, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->ipend &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: %s: unhandled word write %#"PRIregister" to ICPENDR%d\n",
+               v, name, *r, reg - GICD_ICPENDR);
+        return 0;
+
     case GICD_ISACTIVER ... GICD_ISACTIVERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ISACTIVER, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: %s: unhandled word write %#"PRIregister" to ISACTIVER%d\n",
+               v, name, *r, reg - GICD_ISACTIVER);
+        return 0;
+
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, reg - GICD_ICACTIVER, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: %s: unhandled word write %#"PRIregister" to ICACTIVER%d\n",
+               v, name, *r, reg - GICD_ICACTIVER);
+        return 0;
+
     case GICD_IPRIORITYR ... GICD_IPRIORITYRN:
         if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 8, reg - GICD_IPRIORITYR, DABT_WORD);
@@ -496,8 +470,6 @@ static int vgic_v3_rdistr_sgi_mmio_read(struct vcpu *v, mmio_info_t *info,
     struct hsr_dabt dabt = info->dabt;
     struct cpu_user_regs *regs = guest_cpu_user_regs();
     register_t *r = select_user_reg(regs, dabt.reg);
-    struct vgic_irq_rank *rank;
-    unsigned long flags;
 
     switch ( gicr_reg )
     {
@@ -517,22 +489,12 @@ static int vgic_v3_rdistr_sgi_mmio_read(struct vcpu *v, mmio_info_t *info,
           */
         return __vgic_v3_distr_common_mmio_read("vGICR: SGI", v, info,
                                                 gicr_reg);
+
+    /* Read the pending status of an SGI is via GICR is not supported */
     case GICR_ISPENDR0:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicr_reg - GICR_ISPENDR0, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->pendsgi;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
     case GICR_ICPENDR0:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicr_reg - GICR_ICPENDR0, DABT_WORD);
-        if ( rank == NULL ) goto read_as_zero;
-        vgic_lock_rank(v, rank, flags);
-        *r = rank->pendsgi;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        goto read_as_zero;
+
     case GICR_NSACR:
         /* We do not implement security extensions for guests, read zero */
         goto read_as_zero_32;
@@ -562,8 +524,6 @@ static int vgic_v3_rdistr_sgi_mmio_write(struct vcpu *v, mmio_info_t *info,
     struct hsr_dabt dabt = info->dabt;
     struct cpu_user_regs *regs = guest_cpu_user_regs();
     register_t *r = select_user_reg(regs, dabt.reg);
-    struct vgic_irq_rank *rank;
-    unsigned long flags;
 
     switch ( gicr_reg )
     {
@@ -585,22 +545,18 @@ static int vgic_v3_rdistr_sgi_mmio_write(struct vcpu *v, mmio_info_t *info,
                                                  info, gicr_reg);
     case GICR_ISPENDR0:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicr_reg - GICR_ISACTIVER0, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        /* TODO: we just store the SGI pending status. Handle it properly */
-        rank->pendsgi |= *r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: vGICR: SGI: unhandled word write %#"PRIregister" to ISPENDR0\n",
+               v, *r);
+        return 0;
+
     case GICR_ICPENDR0:
         if ( dabt.size != DABT_WORD ) goto bad_width;
-        rank = vgic_rank_offset(v, 1, gicr_reg - GICR_ISACTIVER0, DABT_WORD);
-        if ( rank == NULL ) goto write_ignore;
-        vgic_lock_rank(v, rank, flags);
-        /* TODO: we just store the SGI pending status. Handle it properly */
-        rank->pendsgi &= ~*r;
-        vgic_unlock_rank(v, rank, flags);
-        return 1;
+        printk(XENLOG_G_ERR
+               "%pv: vGICR: SGI: unhandled word write %#"PRIregister" to ICPENDR0\n",
+               v, *r);
+        return 0;
+
     case GICR_NSACR:
         /* We do not implement security extensions for guests, write ignore */
         goto write_ignore_32;
@@ -620,7 +576,6 @@ bad_width:
 
 write_ignore_32:
     if ( dabt.size != DABT_WORD ) goto bad_width;
-write_ignore:
     return 1;
 }
 

diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index 74d5a4e3e34987496e9f2648f9f3a07ad9f550dc..0c7da7f1496b699914197483ccd557dd1f948ad1 100644 (file)
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -85,7 +85,7 @@ struct pending_irq
 /* Represents state corresponding to a block of 32 interrupts */
 struct vgic_irq_rank {
     spinlock_t lock; /* Covers access to all other members of this struct */
-    uint32_t ienable, iactive, ipend, pendsgi;
+    uint32_t ienable;
     uint32_t icfg[2];
     uint32_t ipriority[8];
     union {