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Diffstat (limited to 'arch/arm64/kvm/sys_regs.c')
-rw-r--r--arch/arm64/kvm/sys_regs.c74
1 files changed, 57 insertions, 17 deletions
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index baa65292bbc2..7b45c040cc27 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -44,6 +44,10 @@
* 64bit interface.
*/
+static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
+static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
+static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
+
static bool read_from_write_only(struct kvm_vcpu *vcpu,
struct sys_reg_params *params,
const struct sys_reg_desc *r)
@@ -287,16 +291,55 @@ static bool trap_loregion(struct kvm_vcpu *vcpu,
return trap_raz_wi(vcpu, p, r);
}
+static bool trap_oslar_el1(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
+{
+ u64 oslsr;
+
+ if (!p->is_write)
+ return read_from_write_only(vcpu, p, r);
+
+ /* Forward the OSLK bit to OSLSR */
+ oslsr = __vcpu_sys_reg(vcpu, OSLSR_EL1) & ~SYS_OSLSR_OSLK;
+ if (p->regval & SYS_OSLAR_OSLK)
+ oslsr |= SYS_OSLSR_OSLK;
+
+ __vcpu_sys_reg(vcpu, OSLSR_EL1) = oslsr;
+ return true;
+}
+
static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- if (p->is_write) {
- return ignore_write(vcpu, p);
- } else {
- p->regval = (1 << 3);
- return true;
- }
+ if (p->is_write)
+ return write_to_read_only(vcpu, p, r);
+
+ p->regval = __vcpu_sys_reg(vcpu, r->reg);
+ return true;
+}
+
+static int set_oslsr_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ u64 id = sys_reg_to_index(rd);
+ u64 val;
+ int err;
+
+ err = reg_from_user(&val, uaddr, id);
+ if (err)
+ return err;
+
+ /*
+ * The only modifiable bit is the OSLK bit. Refuse the write if
+ * userspace attempts to change any other bit in the register.
+ */
+ if ((val ^ rd->val) & ~SYS_OSLSR_OSLK)
+ return -EINVAL;
+
+ __vcpu_sys_reg(vcpu, rd->reg) = val;
+ return 0;
}
static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
@@ -1169,10 +1212,6 @@ static bool access_raz_id_reg(struct kvm_vcpu *vcpu,
return __access_id_reg(vcpu, p, r, true);
}
-static int reg_from_user(u64 *val, const void __user *uaddr, u64 id);
-static int reg_to_user(void __user *uaddr, const u64 *val, u64 id);
-static u64 sys_reg_to_index(const struct sys_reg_desc *reg);
-
/* Visibility overrides for SVE-specific control registers */
static unsigned int sve_visibility(const struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
@@ -1423,9 +1462,9 @@ static unsigned int mte_visibility(const struct kvm_vcpu *vcpu,
* Debug handling: We do trap most, if not all debug related system
* registers. The implementation is good enough to ensure that a guest
* can use these with minimal performance degradation. The drawback is
- * that we don't implement any of the external debug, none of the
- * OSlock protocol. This should be revisited if we ever encounter a
- * more demanding guest...
+ * that we don't implement any of the external debug architecture.
+ * This should be revisited if we ever encounter a more demanding
+ * guest...
*/
static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_DC_ISW), access_dcsw },
@@ -1452,8 +1491,9 @@ static const struct sys_reg_desc sys_reg_descs[] = {
DBG_BCR_BVR_WCR_WVR_EL1(15),
{ SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi },
- { SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi },
- { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 },
+ { SYS_DESC(SYS_OSLAR_EL1), trap_oslar_el1 },
+ { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1,
+ SYS_OSLSR_OSLM_IMPLEMENTED, .set_user = set_oslsr_el1, },
{ SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi },
@@ -1925,10 +1965,10 @@ static const struct sys_reg_desc cp14_regs[] = {
DBGBXVR(0),
/* DBGOSLAR */
- { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
+ { Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_oslar_el1 },
DBGBXVR(1),
/* DBGOSLSR */
- { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
+ { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 },
DBGBXVR(2),
DBGBXVR(3),
/* DBGOSDLR */