[Xen-changelog] [xen stable-4.6] xen/arm: ignore writes to GICD_ICACTIVER ... GICD_ICACTIVERN

[patchbot@xxxxxxx]

commit 56b17b013ccf28336417503a80d02c3decff26d7
Author:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
AuthorDate: Tue May 17 11:21:17 2016 +0100
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Tue May 17 11:21:17 2016 +0100

    xen/arm: ignore writes to GICD_ICACTIVER ... GICD_ICACTIVERN
    
    Injecting a fault to the guest just because it is writing to one of the
    GICD_ICACTIVER registers, which are part of the GICv2 and GICv3 specs,
    is harsh. Additionally it causes recent linux kernels to fail to boot on
    Xen.
    
    Ignore writes to GICD_ICACTIVER ... GICD_ICACTIVERN instead, to solve
    the boot issue and for backportability. However implementing the
    registers properly might a better long term solution.
    
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
    Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/vgic-v2.c | 3 +--
 xen/arch/arm/vgic-v3.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index cb1fbb8..55eef5c 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -335,11 +335,10 @@ static int vgic_v2_distr_mmio_write(struct vcpu *v, 
mmio_info_t *info)
         return 0;
 
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
         printk(XENLOG_G_ERR
                "%pv: vGICD: unhandled word write %#"PRIregister" to 
ICACTIVER%d\n",
                v, *r, gicd_reg - GICD_ICACTIVER);
-        return 0;
+        goto write_ignore_32;
 
     case GICD_ITARGETSR ... GICD_ITARGETSR7:
         /* SGI/PPI target is read only */
diff --git a/xen/arch/arm/vgic-v3.c b/xen/arch/arm/vgic-v3.c
index f1c482d..17d5d6d 100644
--- a/xen/arch/arm/vgic-v3.c
+++ b/xen/arch/arm/vgic-v3.c
@@ -427,11 +427,10 @@ static int __vgic_v3_distr_common_mmio_write(const char 
*name, struct vcpu *v,
         return 0;
 
     case GICD_ICACTIVER ... GICD_ICACTIVERN:
-        if ( dabt.size != DABT_WORD ) goto bad_width;
         printk(XENLOG_G_ERR
                "%pv: %s: unhandled word write %#"PRIregister" to 
ICACTIVER%d\n",
                v, name, *r, reg - GICD_ICACTIVER);
-        return 0;
+        goto write_ignore_32;
 
     case GICD_IPRIORITYR ... GICD_IPRIORITYRN:
         if ( dabt.size != DABT_BYTE && dabt.size != DABT_WORD ) goto bad_width;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.6

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