From: Will Deacon <will@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: Marc Zyngier <maz@kernel.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, kvmarm@lists.cs.columbia.edu Subject: [PATCH 3/5] KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall Date: Thu, 23 Sep 2021 12:22:54 +0100 [thread overview] Message-ID: <20210923112256.15767-4-will@kernel.org> (raw) In-Reply-To: <20210923112256.15767-1-will@kernel.org> If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail to propagate the failure code back to kvm_arch_init(). Pass a pointer to a zero-initialised return variable so that failure to finalise the pKVM protections on a host CPU can be reported back to KVM. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> --- arch/arm64/kvm/arm.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9506cf88fa0e..13bbf35896cd 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1986,9 +1986,25 @@ static int init_hyp_mode(void) return err; } -static void _kvm_host_prot_finalize(void *discard) +static void _kvm_host_prot_finalize(void *arg) { - WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)); + int *err = arg; + + if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize))) + WRITE_ONCE(*err, -EINVAL); +} + +static int pkvm_drop_host_privileges(void) +{ + int ret = 0; + + /* + * Flip the static key upfront as that may no longer be possible + * once the host stage 2 is installed. + */ + static_branch_enable(&kvm_protected_mode_initialized); + on_each_cpu(_kvm_host_prot_finalize, &ret, 1); + return ret; } static int finalize_hyp_mode(void) @@ -2002,15 +2018,7 @@ static int finalize_hyp_mode(void) * None of other sections should ever be introspected. */ kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); - - /* - * Flip the static key upfront as that may no longer be possible - * once the host stage 2 is installed. - */ - static_branch_enable(&kvm_protected_mode_initialized); - on_each_cpu(_kvm_host_prot_finalize, NULL, 1); - - return 0; + return pkvm_drop_host_privileges(); } struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr) -- 2.33.0.464.g1972c5931b-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will@kernel.org> To: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>, Quentin Perret <qperret@google.com>, Catalin Marinas <catalin.marinas@arm.com>, Alexandru Elisei <alexandru.elisei@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, kvmarm@lists.cs.columbia.edu Subject: [PATCH 3/5] KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall Date: Thu, 23 Sep 2021 12:22:54 +0100 [thread overview] Message-ID: <20210923112256.15767-4-will@kernel.org> (raw) In-Reply-To: <20210923112256.15767-1-will@kernel.org> If the __pkvm_prot_finalize hypercall returns an error, we WARN but fail to propagate the failure code back to kvm_arch_init(). Pass a pointer to a zero-initialised return variable so that failure to finalise the pKVM protections on a host CPU can be reported back to KVM. Cc: Marc Zyngier <maz@kernel.org> Cc: Quentin Perret <qperret@google.com> Signed-off-by: Will Deacon <will@kernel.org> --- arch/arm64/kvm/arm.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9506cf88fa0e..13bbf35896cd 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1986,9 +1986,25 @@ static int init_hyp_mode(void) return err; } -static void _kvm_host_prot_finalize(void *discard) +static void _kvm_host_prot_finalize(void *arg) { - WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize)); + int *err = arg; + + if (WARN_ON(kvm_call_hyp_nvhe(__pkvm_prot_finalize))) + WRITE_ONCE(*err, -EINVAL); +} + +static int pkvm_drop_host_privileges(void) +{ + int ret = 0; + + /* + * Flip the static key upfront as that may no longer be possible + * once the host stage 2 is installed. + */ + static_branch_enable(&kvm_protected_mode_initialized); + on_each_cpu(_kvm_host_prot_finalize, &ret, 1); + return ret; } static int finalize_hyp_mode(void) @@ -2002,15 +2018,7 @@ static int finalize_hyp_mode(void) * None of other sections should ever be introspected. */ kmemleak_free_part(__hyp_bss_start, __hyp_bss_end - __hyp_bss_start); - - /* - * Flip the static key upfront as that may no longer be possible - * once the host stage 2 is installed. - */ - static_branch_enable(&kvm_protected_mode_initialized); - on_each_cpu(_kvm_host_prot_finalize, NULL, 1); - - return 0; + return pkvm_drop_host_privileges(); } struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr) -- 2.33.0.464.g1972c5931b-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-09-23 11:23 UTC|newest] Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-23 11:22 [PATCH 0/5] KVM: arm64: Restrict host hypercalls when pKVM is enabled Will Deacon 2021-09-23 11:22 ` Will Deacon 2021-09-23 11:22 ` [PATCH 1/5] arm64: Prevent kexec and hibernation if is_protected_kvm_enabled() Will Deacon 2021-09-23 11:22 ` Will Deacon 2021-09-23 11:45 ` Mark Rutland 2021-09-23 11:45 ` Mark Rutland 2021-09-23 12:29 ` Will Deacon 2021-09-23 12:29 ` Will Deacon 2021-09-23 11:22 ` [PATCH 2/5] KVM: arm64: Reject stub hypercalls after pKVM has been initialised Will Deacon 2021-09-23 11:22 ` Will Deacon 2021-09-29 13:37 ` Quentin Perret 2021-09-29 13:37 ` Quentin Perret 2021-09-23 11:22 ` Will Deacon [this message] 2021-09-23 11:22 ` [PATCH 3/5] KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall Will Deacon 2021-09-29 13:36 ` Quentin Perret 2021-09-29 13:36 ` Quentin Perret 2021-10-05 11:30 ` Will Deacon 2021-10-05 11:30 ` Will Deacon 2021-09-23 11:22 ` [PATCH 4/5] KVM: arm64: Prevent re-finalisation of pKVM for a given CPU Will Deacon 2021-09-23 11:22 ` Will Deacon 2021-09-29 13:41 ` Quentin Perret 2021-09-29 13:41 ` Quentin Perret 2021-09-23 11:22 ` [PATCH 5/5] KVM: arm64: Disable privileged hypercalls after pKVM finalisation Will Deacon 2021-09-23 11:22 ` Will Deacon 2021-09-23 12:56 ` Marc Zyngier 2021-09-23 12:56 ` Marc Zyngier 2021-09-23 13:02 ` Will Deacon 2021-09-23 13:02 ` Will Deacon 2021-09-23 13:11 ` Marc Zyngier 2021-09-23 13:11 ` Marc Zyngier 2021-09-23 12:58 ` Will Deacon 2021-09-23 12:58 ` Will Deacon 2021-09-23 12:21 ` [PATCH 0/5] KVM: arm64: Restrict host hypercalls when pKVM is enabled Marc Zyngier 2021-09-23 12:21 ` Marc Zyngier
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