[PATCH v2 4/9] arm64: KVM: Make unexpected reads from WO registers inject an undef
From: Christoffer Dall <hidden>
Date: 2017-03-28 12:45:13
Also in:
kvm, kvmarm
On Mon, Mar 27, 2017 at 05:03:40PM +0100, Marc Zyngier wrote:
Reads from write-only system registers are generally confined to EL1 and not propagated to EL2 (that's what the architecture mantates). In order to be sure that we have a sane behaviour even in the unlikely event that we have a broken system, we still handle it in KVM. In that case, let's inject an undef into the guest. Let's also remove write_to_read_only which isn't used anywhere.
Reviewed-by: Christoffer Dall <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Marc Zyngier <redacted> --- arch/arm64/kvm/sys_regs.c | 9 +++++++++ arch/arm64/kvm/sys_regs.h | 18 ------------------ 2 files changed, 9 insertions(+), 18 deletions(-)diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 5e3ce7890b35..19a036b4f6ac 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c@@ -55,6 +55,15 @@ * 64bit interface. */ +static bool read_from_write_only(struct kvm_vcpu *vcpu, + const struct sys_reg_params *params) +{ + WARN_ONCE(1, "Unexpected sys_reg read to write-only register\n"); + print_sys_reg_instr(params); + kvm_inject_undefined(vcpu); + return false; +} + /* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */ static u32 cache_levels;diff --git a/arch/arm64/kvm/sys_regs.h b/arch/arm64/kvm/sys_regs.h index 9c6ffd0f0196..638f724e45af 100644 --- a/arch/arm64/kvm/sys_regs.h +++ b/arch/arm64/kvm/sys_regs.h@@ -83,24 +83,6 @@ static inline bool read_zero(struct kvm_vcpu *vcpu, return true; } -static inline bool write_to_read_only(struct kvm_vcpu *vcpu, - const struct sys_reg_params *params) -{ - kvm_debug("sys_reg write to read-only register at: %lx\n", - *vcpu_pc(vcpu)); - print_sys_reg_instr(params); - return false; -} - -static inline bool read_from_write_only(struct kvm_vcpu *vcpu, - const struct sys_reg_params *params) -{ - kvm_debug("sys_reg read to write-only register at: %lx\n", - *vcpu_pc(vcpu)); - print_sys_reg_instr(params); - return false; -} - /* Reset functions */ static inline void reset_unknown(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)-- 2.11.0