arm/vpci: mask off upper bits in vPCI read mmio handler

On Arm, we expect read handlers to have the bits above the access size
zeroed. vPCI read handlers may return all 1s. Mask off the bits above
the access size.

Fixes: 9a5e22b64266 ("xen/arm: check read handler behavior")
Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/arch/arm/vpci.c b/xen/arch/arm/vpci.c
index b63a356bb4a881523f06338e9138142b60b2a206..3a3ff5d0812cdf960b67d700f67d8c9eccd86b78 100644 (file)
--- a/xen/arch/arm/vpci.c
+++ b/xen/arch/arm/vpci.c
@@ -37,7 +37,7 @@ static int vpci_mmio_read(struct vcpu *v, mmio_info_t *info,
     if ( vpci_ecam_read(sbdf, ECAM_REG_OFFSET(info->gpa),
                         1U << info->dabt.size, &data) )
     {
-        *r = data;
+        *r = data & invalid;
         return 1;
     }