KVM: arm64: vgic-its: Implement vgic_mmio_uaccess_write_its_creadr

GITS_CREADR needs to be restored so let's implement the associated
uaccess_write_its callback. The write only is allowed if the its
is disabled.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index fd2660d0d6943aba7a074f82e7f498c48c879ed8..bf3ff09315722e476e9734278b1f55ec31900c38 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1213,6 +1213,33 @@ static unsigned long vgic_mmio_read_its_creadr(struct kvm *kvm,
        return extract_bytes(its->creadr, addr & 0x7, len);
 }
 
+static int vgic_mmio_uaccess_write_its_creadr(struct kvm *kvm,
+                                             struct vgic_its *its,
+                                             gpa_t addr, unsigned int len,
+                                             unsigned long val)
+{
+       u32 cmd_offset;
+       int ret = 0;
+
+       mutex_lock(&its->cmd_lock);
+
+       if (its->enabled) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       cmd_offset = ITS_CMD_OFFSET(val);
+       if (cmd_offset >= ITS_CMD_BUFFER_SIZE(its->cbaser)) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       its->creadr = cmd_offset;
+out:
+       mutex_unlock(&its->cmd_lock);
+       return ret;
+}
+
 #define BASER_INDEX(addr) (((addr) / sizeof(u64)) & 0x7)
 static unsigned long vgic_mmio_read_its_baser(struct kvm *kvm,
                                              struct vgic_its *its,
@@ -1317,6 +1344,16 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its,
        .its_write = wr,                                        \
 }
 
+#define REGISTER_ITS_DESC_UACCESS(off, rd, wr, uwr, length, acc)\
+{                                                              \
+       .reg_offset = off,                                      \
+       .len = length,                                          \
+       .access_flags = acc,                                    \
+       .its_read = rd,                                         \
+       .its_write = wr,                                        \
+       .uaccess_its_write = uwr,                               \
+}
+
 static void its_mmio_write_wi(struct kvm *kvm, struct vgic_its *its,
                              gpa_t addr, unsigned int len, unsigned long val)
 {
@@ -1339,8 +1376,9 @@ static struct vgic_register_region its_registers[] = {
        REGISTER_ITS_DESC(GITS_CWRITER,
                vgic_mmio_read_its_cwriter, vgic_mmio_write_its_cwriter, 8,
                VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
-       REGISTER_ITS_DESC(GITS_CREADR,
-               vgic_mmio_read_its_creadr, its_mmio_write_wi, 8,
+       REGISTER_ITS_DESC_UACCESS(GITS_CREADR,
+               vgic_mmio_read_its_creadr, its_mmio_write_wi,
+               vgic_mmio_uaccess_write_its_creadr, 8,
                VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
        REGISTER_ITS_DESC(GITS_BASER,
                vgic_mmio_read_its_baser, vgic_mmio_write_its_baser, 0x40,