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From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
To: xen-devel@lists.xensource.com
Cc: julien.grall@citrix.com, Ian.Campbell@citrix.com,
	Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Subject: [PATCH v9 08/10] xen/arm: take the rank lock before accessing ipriority
Date: Thu, 24 Jul 2014 18:33:10 +0100	[thread overview]
Message-ID: <1406223192-26267-8-git-send-email-stefano.stabellini@eu.citrix.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1407241825570.2293@kaball.uk.xensource.com>

Currently we read ipriority from vgic_vcpu_inject_irq without taking the
rank lock. Fix that by taking the rank lock and reading ipriority at the
beginning of the function.

As vgic_vcpu_inject_irq is called from the irq.c upon receiving an
interrupt, we need to change the implementation of vgic_lock/unlock_rank
to spin_lock_irqsave to make it safe in irq context.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

---

Changes in v9:
- add explicit flags paramter to vgic_lock_rank and vgic_unlock_rank.

Changes in v2:
- rebased on ab78724fc5628318b172b4344f7280621a151e1b;
- remove warning on changing priority of active irqs.
---
 xen/arch/arm/vgic-v2.c     |   74 +++++++++++++++++++++++---------------------
 xen/arch/arm/vgic.c        |   10 ++++--
 xen/include/asm-arm/vgic.h |    4 +--
 3 files changed, 47 insertions(+), 41 deletions(-)

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index f9e357c..8b21a13 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -39,6 +39,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
     register_t *r = select_user_reg(regs, dabt.reg);
     struct vgic_irq_rank *rank;
     int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase);
+    unsigned long flags;
 
     switch ( gicd_reg )
     {
@@ -77,54 +78,54 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ISENABLER, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->ienable;
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ICENABLER ... GICD_ICENABLERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ICENABLER, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->ienable;
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ISPENDR ... GICD_ISPENDRN:
         if ( dabt.size != DABT_BYTE && 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);
+        vgic_lock_rank(v, rank, flags);
         *r = vgic_byte_read(rank->ipend, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        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, gicd_reg - GICD_ICPENDR, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = vgic_byte_read(rank->ipend, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     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);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->iactive;
-        vgic_unlock_rank(v, rank);
+        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);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->iactive;
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ITARGETSR ... GICD_ITARGETSRN:
@@ -132,12 +133,12 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         rank = vgic_rank_offset(v, 8, gicd_reg - GICD_ITARGETSR, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
 
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->itargets[REG_RANK_INDEX(8, gicd_reg - GICD_ITARGETSR,
                                            DABT_WORD)];
         if ( dabt.size == DABT_BYTE )
             *r = vgic_byte_read(*r, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_IPRIORITYR ... GICD_IPRIORITYRN:
@@ -145,21 +146,21 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         rank = vgic_rank_offset(v, 8, gicd_reg - GICD_IPRIORITYR, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
 
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->ipriority[REG_RANK_INDEX(8, gicd_reg - GICD_IPRIORITYR,
                                             DABT_WORD)];
         if ( dabt.size == DABT_BYTE )
             *r = vgic_byte_read(*r, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ICFGR ... GICD_ICFGRN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 2, gicd_reg - GICD_ICFGR, DABT_WORD);
         if ( rank == NULL) goto read_as_zero;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         *r = rank->icfg[REG_RANK_INDEX(2, gicd_reg - GICD_ICFGR, DABT_WORD)];
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_NSACR ... GICD_NSACRN:
@@ -176,18 +177,18 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
         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);
+        vgic_lock_rank(v, rank, flags);
         *r = vgic_byte_read(rank->pendsgi, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        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);
+        vgic_lock_rank(v, rank, flags);
         *r = vgic_byte_read(rank->pendsgi, dabt.sign, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     /* Implementation defined -- read as zero */
@@ -269,6 +270,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
     struct vgic_irq_rank *rank;
     int gicd_reg = (int)(info->gpa - v->domain->arch.vgic.dbase);
     uint32_t tr;
+    unsigned long flags;
 
     switch ( gicd_reg )
     {
@@ -295,7 +297,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ISENABLER, DABT_WORD);
         if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         tr = rank->ienable;
         rank->ienable |= *r;
         /* The virtual irq is derived from register offset.
@@ -303,14 +305,14 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
          * to get Virtual irq number */
         vgic_enable_irqs(v, (*r) & (~tr),
                          (gicd_reg - GICD_ISENABLER) >> DABT_WORD);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ICENABLER ... GICD_ICENABLERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 1, gicd_reg - GICD_ICENABLER, DABT_WORD);
         if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         tr = rank->ienable;
         rank->ienable &= ~*r;
         /* The virtual irq is derived from register offset.
@@ -318,7 +320,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
          * to get  Virtual irq number */
         vgic_disable_irqs(v, (*r) & tr,
                          (gicd_reg - GICD_ICENABLER) >> DABT_WORD);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ISPENDR ... GICD_ISPENDRN:
@@ -337,18 +339,18 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         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);
+        vgic_lock_rank(v, rank, flags);
         rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank);
+        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 write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         rank->iactive &= ~*r;
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ITARGETSR ... GICD_ITARGETSR + 7:
@@ -379,7 +381,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
             !((target & 0xff) && (target & (0xff << 8)) &&
              (target & (0xff << 16)) && (target & (0xff << 24))))
             goto write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         i = 0;
         while ( (i = find_next_bit(&target, 32, i)) < 32 )
         {
@@ -406,7 +408,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         else
             vgic_byte_write(&rank->itargets[REG_RANK_INDEX(8,
                        gicd_reg - GICD_ITARGETSR, DABT_WORD)], target, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
     }
 
@@ -414,14 +416,14 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 8, gicd_reg - GICD_IPRIORITYR, DABT_WORD);
         if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         if ( dabt.size == DABT_WORD )
             rank->ipriority[REG_RANK_INDEX(8, gicd_reg - GICD_IPRIORITYR,
                                            DABT_WORD)] = *r;
         else
             vgic_byte_write(&rank->ipriority[REG_RANK_INDEX(8,
                         gicd_reg - GICD_IPRIORITYR, DABT_WORD)], *r, gicd_reg);
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_ICFGR: /* SGIs */
@@ -433,9 +435,9 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 2, gicd_reg - GICD_ICFGR, DABT_WORD);
         if ( rank == NULL) goto write_ignore;
-        vgic_lock_rank(v, rank);
+        vgic_lock_rank(v, rank, flags);
         rank->icfg[REG_RANK_INDEX(2, gicd_reg - GICD_ICFGR, DABT_WORD)] = *r;
-        vgic_unlock_rank(v, rank);
+        vgic_unlock_rank(v, rank, flags);
         return 1;
 
     case GICD_NSACR ... GICD_NSACRN:
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 474eebd..a3df18d 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -158,10 +158,11 @@ struct vcpu *vgic_get_target_vcpu(struct vcpu *v, unsigned int irq)
     struct domain *d = v->domain;
     struct vcpu *v_target;
     struct vgic_irq_rank *rank = vgic_rank_irq(v, irq);
+    unsigned long flags;
 
-    vgic_lock_rank(v, rank);
+    vgic_lock_rank(v, rank, flags);
     v_target = d->arch.vgic.handler->get_target_vcpu(v, irq);
-    vgic_unlock_rank(v, rank);
+    vgic_unlock_rank(v, rank, flags);
     return v_target;
 }
 
@@ -367,6 +368,10 @@ void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq)
     unsigned long flags;
     bool_t running;
 
+    vgic_lock_rank(v, rank, flags);
+    priority = vgic_byte_read(rank->ipriority[REG_RANK_INDEX(8, irq, DABT_WORD)], 0, irq & 0x3);
+    vgic_unlock_rank(v, rank, flags);
+
     spin_lock_irqsave(&v->arch.vgic.lock, flags);
 
     /* vcpu offline */
@@ -384,7 +389,6 @@ void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq)
         goto out;
     }
  
-    priority = vgic_byte_read(rank->ipriority[REG_RANK_INDEX(8, irq, DABT_WORD)], 0, irq & 0x3);
 
     n->irq = irq;
     n->priority = priority;
diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h
index 9b1db04..338ba03 100644
--- a/xen/include/asm-arm/vgic.h
+++ b/xen/include/asm-arm/vgic.h
@@ -107,8 +107,8 @@ struct vgic_ops {
 #define vgic_lock(v)   spin_lock_irq(&(v)->domain->arch.vgic.lock)
 #define vgic_unlock(v) spin_unlock_irq(&(v)->domain->arch.vgic.lock)
 
-#define vgic_lock_rank(v, r) spin_lock(&(r)->lock)
-#define vgic_unlock_rank(v, r) spin_unlock(&(r)->lock)
+#define vgic_lock_rank(v, r, flags)   spin_lock_irqsave(&(r)->lock, flags)
+#define vgic_unlock_rank(v, r, flags) spin_unlock_irqrestore(&(r)->lock, flags)
 
 /*
  * Rank containing GICD_<FOO><n> for GICD_<FOO> with
-- 
1.7.10.4

  parent reply	other threads:[~2014-07-24 17:33 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-24 17:31 [PATCH v9 00/10] gic and vgic fixes and improvements Stefano Stabellini
2014-07-24 17:33 ` [PATCH v9 01/10] xen/arm: observe itargets setting in vgic_enable_irqs and vgic_disable_irqs Stefano Stabellini
2014-07-24 17:33 ` [PATCH v9 02/10] xen/arm: move setting GIC_IRQ_GUEST_QUEUED earlier Stefano Stabellini
2014-07-28 15:16   ` Julien Grall
2014-07-28 16:18     ` Stefano Stabellini
2014-07-24 17:33 ` [PATCH v9 03/10] xen/arm: inflight irqs during migration Stefano Stabellini
2014-07-24 17:33 ` [PATCH v9 04/10] xen/arm: support irq delivery to vcpu > 0 Stefano Stabellini
2014-07-28 16:16   ` Julien Grall
2014-07-24 17:33 ` [PATCH v9 05/10] xen/arm: physical irq follow virtual irq Stefano Stabellini
2014-07-28 15:47   ` Julien Grall
2014-07-28 16:20     ` Stefano Stabellini
2014-07-28 16:42       ` Julien Grall
2014-08-01 17:22         ` Stefano Stabellini
2014-08-01 17:54           ` Julien Grall
2014-08-01 17:58             ` Stefano Stabellini
2014-08-01 18:00               ` Julien Grall
2014-07-24 17:33 ` [PATCH v9 06/10] xen: introduce sched_move_irqs Stefano Stabellini
2014-07-24 17:33 ` [PATCH v9 07/10] xen: remove workaround to inject evtchn_irq on irq enable Stefano Stabellini
2014-07-25  8:12   ` Jan Beulich
2014-08-01 17:00     ` Stefano Stabellini
2014-08-04  7:15       ` Jan Beulich
2014-08-04 10:02         ` Stefano Stabellini
2014-08-04 10:18           ` Jan Beulich
2014-08-04 20:29             ` Stefano Stabellini
2014-08-05  6:25               ` Jan Beulich
2014-08-05 11:26                 ` Stefano Stabellini
2014-07-24 17:33 ` Stefano Stabellini [this message]
2014-07-28 16:22   ` [PATCH v9 08/10] xen/arm: take the rank lock before accessing ipriority Julien Grall
2014-07-24 17:33 ` [PATCH v9 09/10] xen: introduce bit access macros for the IRQ line status flags Stefano Stabellini
2014-07-25 12:21   ` Julien Grall
2014-07-24 17:33 ` [PATCH v9 10/10] xen/arm: make accesses to desc->status flags atomic Stefano Stabellini
2014-07-25 12:40   ` Julien Grall
2014-07-28 16:31     ` Stefano Stabellini
2014-07-28 17:14   ` Julien Grall
2014-07-29 10:25     ` Stefano Stabellini

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