From: Julien Grall <julien.grall@linaro.org>
Date: Mon, 16 Feb 2015 14:50:51 +0000 (+0000)
Subject: xen/arm: vgic-v2: Correctly handle RAZ/WI registers
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~3737
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=1fefa550274758204a6bf58ea9b9509296197080;p=xen.git

xen/arm: vgic-v2: Correctly handle RAZ/WI registers

All the GICv2 registers are word-accessible. Some them are also
byte-accessible (see GICD_IPRIORITYR*).

Those registers are incorrectly implemented when they should be RAZ. Only
word-access size are currently allowed for them.

To avoid further issues, introduce different label following the access-size
of the registers:
    - read_as_zero_32 and write_ignore_32: Used for registers accessible
    via a word.
    - read_as_zero: Used when we don't have to check the access size.

The latter is used when the access size has already been checked in the
register emulation and/or when the register offset is reserved/implementation
defined.

Note that, only used labels has been introduced.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 0cf82efeba..84790279c9 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -74,7 +74,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
 
     case GICD_IGROUPR ... GICD_IGROUPRN:
         /* We do not implement security extensions for guests, read zero */
-        goto read_as_zero;
+        goto read_as_zero_32;
 
     case GICD_ISENABLER ... GICD_ISENABLERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
@@ -166,7 +166,7 @@ static int vgic_v2_distr_mmio_read(struct vcpu *v, mmio_info_t *info)
 
     case GICD_NSACR ... GICD_NSACRN:
         /* We do not implement security extensions for guests, read zero */
-        goto read_as_zero;
+        goto read_as_zero_32;
 
     case GICD_SGIR:
         if ( dabt.size != DABT_WORD ) goto bad_width;
@@ -226,8 +226,9 @@ bad_width:
     domain_crash_synchronous();
     return 0;
 
-read_as_zero:
+read_as_zero_32:
     if ( dabt.size != DABT_WORD ) goto bad_width;
+read_as_zero:
     *r = 0;
     return 1;
 }
@@ -289,7 +290,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
     /* R/O -- write ignored */
     case GICD_TYPER:
     case GICD_IIDR:
-        goto write_ignore;
+        goto write_ignore_32;
 
     /* Implementation defined -- write ignored */
     case 0x020 ... 0x03c:
@@ -297,7 +298,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
 
     case GICD_IGROUPR ... GICD_IGROUPRN:
         /* We do not implement security extensions for guests, write ignore */
-        goto write_ignore;
+        goto write_ignore_32;
 
     case GICD_ISENABLER ... GICD_ISENABLERN:
         if ( dabt.size != DABT_WORD ) goto bad_width;
@@ -363,7 +364,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
 
     case GICD_ITARGETSR ... GICD_ITARGETSR + 7:
         /* SGI/PPI target is read only */
-        goto write_ignore;
+        goto write_ignore_32;
 
     case GICD_ITARGETSR + 8 ... GICD_ITARGETSRN:
     {
@@ -436,10 +437,10 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
         return 1;
 
     case GICD_ICFGR: /* SGIs */
-        goto write_ignore;
+        goto write_ignore_32;
     case GICD_ICFGR + 1: /* PPIs */
         /* It is implementation defined if these are writeable. We chose not */
-        goto write_ignore;
+        goto write_ignore_32;
     case GICD_ICFGR + 2 ... GICD_ICFGRN: /* SPIs */
         if ( dabt.size != DABT_WORD ) goto bad_width;
         rank = vgic_rank_offset(v, 2, gicd_reg - GICD_ICFGR, DABT_WORD);
@@ -451,7 +452,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
 
     case GICD_NSACR ... GICD_NSACRN:
         /* We do not implement security extensions for guests, write ignore */
-        goto write_ignore;
+        goto write_ignore_32;
 
     case GICD_SGIR:
         if ( dabt.size != DABT_WORD ) goto bad_width;
@@ -477,7 +478,7 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, mmio_info_t *info)
 
     /* R/O -- write ignore */
     case GICD_ICPIDR2:
-        goto write_ignore;
+        goto write_ignore_32;
 
     /* Implementation defined -- write ignored */
     case 0xfec ... 0xffc:
@@ -506,8 +507,9 @@ bad_width:
     domain_crash_synchronous();
     return 0;
 
-write_ignore:
+write_ignore_32:
     if ( dabt.size != DABT_WORD ) goto bad_width;
+write_ignore:
     return 1;
 }