[PATCH] KVM: arm64: Fix 64 bit mmio handle

From: Schspa Shi
Date: Thu Jun 30 2022 - 12:12:36 EST


If the len is 8 bytes, we can't get the correct sign extend for
be system.

Fix the mask type len and the comparison of length.

Signed-off-by: Schspa Shi <schspa@xxxxxxxxx>
---
arch/arm64/kvm/mmio.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c
index 3dd38a151d2a6..0692f8b18f35c 100644
--- a/arch/arm64/kvm/mmio.c
+++ b/arch/arm64/kvm/mmio.c
@@ -81,8 +81,8 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len)
int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
{
unsigned long data;
+ unsigned long mask;
unsigned int len;
- int mask;

/* Detect an already handled MMIO return */
if (unlikely(!vcpu->mmio_needed))
@@ -97,7 +97,7 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu)
data = kvm_mmio_read_buf(run->mmio.data, len);

if (kvm_vcpu_dabt_issext(vcpu) &&
- len < sizeof(unsigned long)) {
+ len <= sizeof(unsigned long)) {
mask = 1U << ((len * 8) - 1);
data = (data ^ mask) - mask;
}
--
2.37.0