arm/arm64: KVM: Add smccc accessors to PSCI code

Commit 84684fecd7ea upstream.

Instead of open coding the accesses to the various registers,
let's add explicit SMCCC accessors.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ce15f32d48840bbaf49bf5b9ba540befb59548cb)

CVE-2017-5753
CVE-2017-5715
CVE-2017-5754

Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c
index 999f94d6bb98249794f2fdee438bca375d8e7f9e..c41553d3511038a59a6e7f4d1bbd155722d6b31c 100644 (file)
--- a/virt/kvm/arm/psci.c
+++ b/virt/kvm/arm/psci.c
@@ -32,6 +32,38 @@
 
 #define AFFINITY_MASK(level)   ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
 
+static u32 smccc_get_function(struct kvm_vcpu *vcpu)
+{
+       return vcpu_get_reg(vcpu, 0);
+}
+
+static unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu)
+{
+       return vcpu_get_reg(vcpu, 1);
+}
+
+static unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu)
+{
+       return vcpu_get_reg(vcpu, 2);
+}
+
+static unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu)
+{
+       return vcpu_get_reg(vcpu, 3);
+}
+
+static void smccc_set_retval(struct kvm_vcpu *vcpu,
+                            unsigned long a0,
+                            unsigned long a1,
+                            unsigned long a2,
+                            unsigned long a3)
+{
+       vcpu_set_reg(vcpu, 0, a0);
+       vcpu_set_reg(vcpu, 1, a1);
+       vcpu_set_reg(vcpu, 2, a2);
+       vcpu_set_reg(vcpu, 3, a3);
+}
+
 static unsigned long psci_affinity_mask(unsigned long affinity_level)
 {
        if (affinity_level <= 3)
@@ -77,7 +109,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
        unsigned long context_id;
        phys_addr_t target_pc;
 
-       cpu_id = vcpu_get_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
+       cpu_id = smccc_get_arg1(source_vcpu) & MPIDR_HWID_BITMASK;
        if (vcpu_mode_is_32bit(source_vcpu))
                cpu_id &= ~((u32) 0);
 
@@ -96,8 +128,8 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
                        return PSCI_RET_INVALID_PARAMS;
        }
 
-       target_pc = vcpu_get_reg(source_vcpu, 2);
-       context_id = vcpu_get_reg(source_vcpu, 3);
+       target_pc = smccc_get_arg2(source_vcpu);
+       context_id = smccc_get_arg3(source_vcpu);
 
        kvm_reset_vcpu(vcpu);
 
@@ -116,7 +148,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
         * NOTE: We always update r0 (or x0) because for PSCI v0.1
         * the general puspose registers are undefined upon CPU_ON.
         */
-       vcpu_set_reg(vcpu, 0, context_id);
+       smccc_set_retval(vcpu, context_id, 0, 0, 0);
        vcpu->arch.power_off = false;
        smp_mb();               /* Make sure the above is visible */
 
@@ -136,8 +168,8 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
        struct kvm *kvm = vcpu->kvm;
        struct kvm_vcpu *tmp;
 
-       target_affinity = vcpu_get_reg(vcpu, 1);
-       lowest_affinity_level = vcpu_get_reg(vcpu, 2);
+       target_affinity = smccc_get_arg1(vcpu);
+       lowest_affinity_level = smccc_get_arg2(vcpu);
 
        /* Determine target affinity mask */
        target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
@@ -210,7 +242,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
 static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
 {
        struct kvm *kvm = vcpu->kvm;
-       unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
+       u32 psci_fn = smccc_get_function(vcpu);
        unsigned long val;
        int ret = 1;
 
@@ -277,14 +309,14 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
                break;
        }
 
-       vcpu_set_reg(vcpu, 0, val);
+       smccc_set_retval(vcpu, val, 0, 0, 0);
        return ret;
 }
 
 static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
 {
        struct kvm *kvm = vcpu->kvm;
-       unsigned long psci_fn = vcpu_get_reg(vcpu, 0) & ~((u32) 0);
+       u32 psci_fn = smccc_get_function(vcpu);
        unsigned long val;
 
        switch (psci_fn) {
@@ -302,7 +334,7 @@ static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
                break;
        }
 
-       vcpu_set_reg(vcpu, 0, val);
+       smccc_set_retval(vcpu, val, 0, 0, 0);
        return 1;
 }