From: Dave Martin <Dave.Martin@arm.com>
Date: Tue, 11 Dec 2018 20:31:08 +0000
Subject: KVM: arm64: Reject ioctl access to FPSIMD V-regs on SVE vcpus
Git-commit: 8c86dfe39d5d3c91fb201b67b72826f75bd2b655 (partial)
Patch-mainline: v5.2-rc1
References: bsc#1174726
In order to avoid the pointless complexity of maintaining two ioctl
register access views of the same data, this patch blocks ioctl
access to the FPSIMD V-registers on vcpus that support SVE.
This will make it more straightforward to add SVE register access
support.
Since SVE is an opt-in feature for userspace, this will not affect
existing users.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
[mb: drop KVM_REG_ARM64_SVE case]
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
arch/arm64/kvm/guest.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -53,12 +53,19 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu
return 0;
}
+static bool core_reg_offset_is_vreg(u64 off)
+{
+ return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
+ off < KVM_REG_ARM_CORE_REG(fp_regs.fpsr);
+}
+
static u64 core_reg_offset_from_id(u64 id)
{
return id & ~(KVM_REG_ARCH_MASK | KVM_REG_SIZE_MASK | KVM_REG_ARM_CORE);
}
-static int validate_core_offset(const struct kvm_one_reg *reg)
+static int validate_core_offset(const struct kvm_vcpu *vcpu,
+ const struct kvm_one_reg *reg)
{
u64 off = core_reg_offset_from_id(reg->id);
int size;
@@ -90,11 +97,11 @@ static int validate_core_offset(const st
return -EINVAL;
}
- if (KVM_REG_SIZE(reg->id) == size &&
- IS_ALIGNED(off, size / sizeof(__u32)))
- return 0;
+ if (KVM_REG_SIZE(reg->id) != size ||
+ !IS_ALIGNED(off, size / sizeof(__u32)))
+ return -EINVAL;
- return -EINVAL;
+ return 0;
}
static int get_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
@@ -116,7 +123,7 @@ static int get_core_reg(struct kvm_vcpu
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
- if (validate_core_offset(reg))
+ if (validate_core_offset(vcpu, reg))
return -EINVAL;
if (copy_to_user(uaddr, ((u32 *)regs) + off, KVM_REG_SIZE(reg->id)))
@@ -141,7 +148,7 @@ static int set_core_reg(struct kvm_vcpu
(off + (KVM_REG_SIZE(reg->id) / sizeof(__u32))) >= nr_regs)
return -ENOENT;
- if (validate_core_offset(reg))
+ if (validate_core_offset(vcpu, reg))
return -EINVAL;
if (KVM_REG_SIZE(reg->id) > sizeof(tmp))
@@ -194,7 +201,8 @@ int kvm_arch_vcpu_ioctl_set_regs(struct
return -EINVAL;
}
-static int kvm_arm_copy_core_reg_indices(u64 __user *uindices)
+static int copy_core_reg_indices(const struct kvm_vcpu *vcpu,
+ u64 __user *uindices)
{
unsigned int i;
int n = 0;
@@ -213,9 +221,9 @@ static int kvm_arm_copy_core_reg_indices
return n;
}
-static unsigned long num_core_regs(void)
+static unsigned long num_core_regs(const struct kvm_vcpu *vcpu)
{
- return kvm_arm_copy_core_reg_indices(NULL);
+ return copy_core_reg_indices(vcpu, NULL);
}
/**
@@ -280,7 +288,7 @@ unsigned long kvm_arm_num_regs(struct kv
{
unsigned long res = 0;
- res += num_core_regs();
+ res += num_core_regs(vcpu);
res += kvm_arm_num_sys_reg_descs(vcpu);
res += kvm_arm_get_fw_num_regs(vcpu);
res += NUM_TIMER_REGS;
@@ -297,7 +305,7 @@ int kvm_arm_copy_reg_indices(struct kvm_
{
int ret;
- ret = kvm_arm_copy_core_reg_indices(uindices);
+ ret = copy_core_reg_indices(vcpu, uindices);
if (ret)
return ret;
uindices += ret;