From: Oliver Upton <oupton@google.com>
To: Andrew Jones <drjones@redhat.com>
Cc: Reiji Watanabe <reijiw@google.com>,
kvmarm@lists.cs.columbia.edu, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <Alexandru.Elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Peter Shier <pshier@google.com>,
Ricardo Koller <ricarkol@google.com>,
Raghavendra Rao Anata <rananta@google.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH v2 03/11] KVM: arm64: Encapsulate reset request logic in a helper function
Date: Tue, 5 Oct 2021 08:05:02 -0700 [thread overview]
Message-ID: <CAOQ_QsgwK=qyeaUtNJeZ1OWQwaFUAQcy6uopnDuyDA3Qyt7gmw@mail.gmail.com> (raw)
In-Reply-To: <20211005133335.y4k5qv7d3g74nnzx@gator.home>
Hi folks,
On Tue, Oct 5, 2021 at 6:33 AM Andrew Jones <drjones@redhat.com> wrote:
>
> On Fri, Oct 01, 2021 at 09:10:14AM -0700, Oliver Upton wrote:
> > On Thu, Sep 30, 2021 at 11:05 PM Reiji Watanabe <reijiw@google.com> wrote:
> > >
> > > On Thu, Sep 23, 2021 at 12:16 PM Oliver Upton <oupton@google.com> wrote:
> > > >
> > > > In its implementation of the PSCI function, KVM needs to request that a
> > > > target vCPU resets before its next entry into the guest. Wrap the logic
> > > > for requesting a reset in a function for later use by other implemented
> > > > PSCI calls.
> > > >
> > > > No functional change intended.
> > > >
> > > > Signed-off-by: Oliver Upton <oupton@google.com>
> > > > ---
> > > > arch/arm64/kvm/psci.c | 59 +++++++++++++++++++++++++------------------
> > > > 1 file changed, 35 insertions(+), 24 deletions(-)
> > > >
> > > > diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c
> > > > index 310b9cb2b32b..bb59b692998b 100644
> > > > --- a/arch/arm64/kvm/psci.c
> > > > +++ b/arch/arm64/kvm/psci.c
> > > > @@ -64,9 +64,40 @@ static inline bool kvm_psci_valid_affinity(unsigned long affinity)
> > > > return !(affinity & ~MPIDR_HWID_BITMASK);
> > > > }
> > > >
> > > > -static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> > > > +static void kvm_psci_vcpu_request_reset(struct kvm_vcpu *vcpu,
> > > > + unsigned long entry_addr,
> > > > + unsigned long context_id,
> > > > + bool big_endian)
> > > > {
> > > > struct vcpu_reset_state *reset_state;
> > > > +
> > > > + lockdep_assert_held(&vcpu->kvm->lock);
> > > > +
> > > > + reset_state = &vcpu->arch.reset_state;
> > > > + reset_state->pc = entry_addr;
> > > > +
> > > > + /* Propagate caller endianness */
> > > > + reset_state->be = big_endian;
> > > > +
> > > > + /*
> > > > + * NOTE: We always update r0 (or x0) because for PSCI v0.1
> > > > + * the general purpose registers are undefined upon CPU_ON.
> > > > + */
> > > > + reset_state->r0 = context_id;
> > > > +
> > > > + WRITE_ONCE(reset_state->reset, true);
> > > > + kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);
> > > > +
> > > > + /*
> > > > + * Make sure the reset request is observed if the change to
> > > > + * power_state is observed.
> > > > + */
> > > > + smp_wmb();
> > > > + vcpu->arch.power_off = false;
> > > > +}
> > > > +
> > > > +static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> > > > +{
> > > > struct kvm *kvm = source_vcpu->kvm;
> > > > struct kvm_vcpu *vcpu = NULL;
> > > > unsigned long cpu_id;
> > > > @@ -90,29 +121,9 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> > > > return PSCI_RET_INVALID_PARAMS;
> > > > }
> > > >
> > > > - reset_state = &vcpu->arch.reset_state;
> > > > -
> > > > - reset_state->pc = smccc_get_arg2(source_vcpu);
> > > > -
> > > > - /* Propagate caller endianness */
> > > > - reset_state->be = kvm_vcpu_is_be(source_vcpu);
> > > > -
> > > > - /*
> > > > - * NOTE: We always update r0 (or x0) because for PSCI v0.1
> > > > - * the general purpose registers are undefined upon CPU_ON.
> > > > - */
> > > > - reset_state->r0 = smccc_get_arg3(source_vcpu);
> > > > -
> > > > - WRITE_ONCE(reset_state->reset, true);
> > > > - kvm_make_request(KVM_REQ_VCPU_RESET, vcpu);
> > > > -
> > > > - /*
> > > > - * Make sure the reset request is observed if the change to
> > > > - * power_state is observed.
> > > > - */
> > > > - smp_wmb();
> > > > -
> > > > - vcpu->arch.power_off = false;
> > > > + kvm_psci_vcpu_request_reset(vcpu, smccc_get_arg2(source_vcpu),
> > > > + smccc_get_arg3(source_vcpu),
> > > > + kvm_vcpu_is_be(source_vcpu));
> > > > kvm_vcpu_wake_up(vcpu);
> > > >
> > > > return PSCI_RET_SUCCESS;
> > > > --
> > > > 2.33.0.685.g46640cef36-goog
> > >
> > > Reviewed-by: Reiji Watanabe <reijiw@google.com>
> > >
> > > Not directly related to the patch, but the (original) code doesn't
> > > do any sanity checking for the entry address although the PSCI spec says:
> > >
> > > "INVALID_ADDRESS is returned when the entry point address is known
> > > by the implementation to be invalid, because it is in a range that
> > > is known not to be available to the caller."
> >
> > Right, I had noticed the same but was a tad too lazy to address in
> > this series :) Thanks for the review, Reji!
> >
>
> KVM doesn't reserve any subrange within [0 - max_ipa), afaik. So all
> we need to do is check 'entry_addr < max_ipa', right?
>
We could be a bit more pedantic and check if the IPA exists in a
memory slot, seems like kvm_vcpu_is_visible_gfn() should do the trick.
Thoughts?
--
Thanks,
Oliver
next prev parent reply other threads:[~2021-10-05 15:05 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 19:15 [PATCH v2 00/11] KVM: arm64: Implement PSCI SYSTEM_SUSPEND support Oliver Upton
2021-09-23 19:16 ` [PATCH v2 01/11] KVM: arm64: Drop unused vcpu param to kvm_psci_valid_affinity() Oliver Upton
2021-10-01 3:50 ` Reiji Watanabe
2021-10-05 13:22 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 02/11] KVM: arm64: Clean up SMC64 PSCI filtering for AArch32 guests Oliver Upton
2021-10-01 3:56 ` Reiji Watanabe
2021-10-05 13:23 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 03/11] KVM: arm64: Encapsulate reset request logic in a helper function Oliver Upton
2021-10-01 6:04 ` Reiji Watanabe
2021-10-01 16:10 ` Oliver Upton
2021-10-05 13:33 ` Andrew Jones
2021-10-05 15:05 ` Oliver Upton [this message]
2021-10-05 19:01 ` Andrew Jones
2021-10-13 4:48 ` Reiji Watanabe
2021-10-05 13:35 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 04/11] KVM: arm64: Rename the KVM_REQ_SLEEP handler Oliver Upton
2021-10-05 13:34 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 05/11] KVM: arm64: Defer WFI emulation as a requested event Oliver Upton
2021-09-30 10:50 ` Marc Zyngier
2021-09-30 17:09 ` Sean Christopherson
2021-09-30 17:32 ` Oliver Upton
2021-09-30 18:08 ` Sean Christopherson
2021-09-30 21:57 ` Oliver Upton
2021-10-01 13:57 ` Marc Zyngier
2021-09-23 19:16 ` [PATCH v2 06/11] KVM: arm64: Add support for SYSTEM_SUSPEND PSCI call Oliver Upton
2021-09-30 12:29 ` Marc Zyngier
2021-09-30 17:19 ` Sean Christopherson
2021-09-30 17:35 ` Oliver Upton
2021-09-30 17:40 ` Oliver Upton
2021-10-01 14:02 ` Marc Zyngier
2021-10-05 16:02 ` Oliver Upton
2021-09-23 19:16 ` [PATCH v2 07/11] selftests: KVM: Rename psci_cpu_on_test to psci_test Oliver Upton
2021-10-05 13:36 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 08/11] selftests: KVM: Create helper for making SMCCC calls Oliver Upton
2021-10-05 13:39 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 09/11] selftests: KVM: Use KVM_SET_MP_STATE to power off vCPU in psci_test Oliver Upton
2021-09-23 19:16 ` [PATCH v2 10/11] selftests: KVM: Refactor psci_test to make it amenable to new tests Oliver Upton
2021-10-05 13:45 ` Andrew Jones
2021-10-05 14:54 ` Oliver Upton
2021-10-05 19:05 ` Andrew Jones
2021-09-23 19:16 ` [PATCH v2 11/11] selftests: KVM: Test SYSTEM_SUSPEND PSCI call Oliver Upton
2021-10-05 13:49 ` Andrew Jones
2021-10-05 15:07 ` Oliver Upton
2021-09-23 20:15 ` [PATCH v2 00/11] KVM: arm64: Implement PSCI SYSTEM_SUSPEND support Oliver Upton
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