KVM: arm64: Add get_reg_by_id() as a sys_reg_desc retrieving helper

find_reg_by_id() requires a sys_reg_param as input, which most
users provide as a on-stack variable, but don't make any use of
the result.

Provide a helper that doesn't have this requirement and simplify
the callers (all but one).

Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c06c047..1f41028 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -2650,21 +2650,29 @@ const struct sys_reg_desc *find_reg_by_id(u64 id,
        return find_reg(params, table, num);
 }
 
+const struct sys_reg_desc *get_reg_by_id(u64 id,
+                                        const struct sys_reg_desc table[],
+                                        unsigned int num)
+{
+       struct sys_reg_params params;
+
+       if (!index_to_params(id, &params))
+               return NULL;
+
+       return find_reg(&params, table, num);
+}
+
 /* Decode an index value, and find the sys_reg_desc entry. */
 static const struct sys_reg_desc *index_to_sys_reg_desc(struct kvm_vcpu *vcpu,
                                                    u64 id)
 {
        const struct sys_reg_desc *r;
-       struct sys_reg_params params;
 
        /* We only do sys_reg for now. */
        if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM64_SYSREG)
                return NULL;
 
-       if (!index_to_params(id, &params))
-               return NULL;
-
-       r = find_reg(&params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
+       r = get_reg_by_id(id, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
 
        /* Not saved in the sys_reg array and not otherwise accessible? */
        if (r && !(r->reg || r->get_user))
@@ -2723,11 +2731,10 @@ static int reg_to_user(void __user *uaddr, const u64 *val, u64 id)
 
 static int get_invariant_sys_reg(u64 id, void __user *uaddr)
 {
-       struct sys_reg_params params;
        const struct sys_reg_desc *r;
 
-       r = find_reg_by_id(id, &params, invariant_sys_regs,
-                          ARRAY_SIZE(invariant_sys_regs));
+       r = get_reg_by_id(id, invariant_sys_regs,
+                         ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;
 
@@ -2736,13 +2743,12 @@ static int get_invariant_sys_reg(u64 id, void __user *uaddr)
 
 static int set_invariant_sys_reg(u64 id, void __user *uaddr)
 {
-       struct sys_reg_params params;
        const struct sys_reg_desc *r;
        int err;
        u64 val = 0; /* Make sure high bits are 0 for 32-bit regs */
 
-       r = find_reg_by_id(id, &params, invariant_sys_regs,
-                          ARRAY_SIZE(invariant_sys_regs));
+       r = get_reg_by_id(id, invariant_sys_regs,
+                         ARRAY_SIZE(invariant_sys_regs));
        if (!r)
                return -ENOENT;
 

diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h
index aee8ea0..ce30ed9 100644 (file)
--- a/arch/arm64/kvm/sys_regs.h
+++ b/arch/arm64/kvm/sys_regs.h
@@ -195,6 +195,10 @@ const struct sys_reg_desc *find_reg_by_id(u64 id,
                                          const struct sys_reg_desc table[],
                                          unsigned int num);
 
+const struct sys_reg_desc *get_reg_by_id(u64 id,
+                                        const struct sys_reg_desc table[],
+                                        unsigned int num);
+
 #define AA32(_x)       .aarch32_map = AA32_##_x
 #define Op0(_x)        .Op0 = _x
 #define Op1(_x)        .Op1 = _x

diff --git a/arch/arm64/kvm/vgic-sys-reg-v3.c b/arch/arm64/kvm/vgic-sys-reg-v3.c
index 07d5271..644acda 100644 (file)
--- a/arch/arm64/kvm/vgic-sys-reg-v3.c
+++ b/arch/arm64/kvm/vgic-sys-reg-v3.c
@@ -263,14 +263,10 @@ static const struct sys_reg_desc gic_v3_icc_reg_descs[] = {
 int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
                                u64 *reg)
 {
-       struct sys_reg_params params;
        u64 sysreg = (id & KVM_DEV_ARM_VGIC_SYSREG_MASK) | KVM_REG_SIZE_U64;
 
-       params.regval = *reg;
-       params.is_write = is_write;
-
-       if (find_reg_by_id(sysreg, &params, gic_v3_icc_reg_descs,
-                             ARRAY_SIZE(gic_v3_icc_reg_descs)))
+       if (get_reg_by_id(sysreg, gic_v3_icc_reg_descs,
+                         ARRAY_SIZE(gic_v3_icc_reg_descs)))
                return 0;
 
        return -ENXIO;