From: Oliver Upton <oliver.upton@linux.dev>
To: Anish Moorthy <amoorthy@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Marc Zyngier <maz@kernel.org>,
Sean Christopherson <seanjc@google.com>,
James Houghton <jthoughton@google.com>,
Ben Gardon <bgardon@google.com>,
David Matlack <dmatlack@google.com>,
Ricardo Koller <ricarkol@google.com>,
Chao Peng <chao.p.peng@linux.intel.com>,
Axel Rasmussen <axelrasmussen@google.com>,
kvm@vger.kernel.org, kvmarm@lists.linux.dev
Subject: Re: [PATCH 7/8] kvm/arm64: Implement KVM_CAP_MEM_FAULT_NOWAIT for arm64
Date: Wed, 15 Feb 2023 23:37:58 +0000 [thread overview]
Message-ID: <Y+1s1txXLkwdlF6F@linux.dev> (raw)
In-Reply-To: <CAF7b7mpbAdQtvXCQCk5kLrSn0bN=fLYVzEWXVW34OgBSxzHA_g@mail.gmail.com>
On Wed, Feb 15, 2023 at 03:28:31PM -0800, Anish Moorthy wrote:
> On Wed, Feb 15, 2023 at 10:24 AM Oliver Upton <oliver.upton@linux.dev> wrote:
> >
> > All of Sean's suggestions about writing a change description apply here
> > too.
>
> Ack
>
> > > + if (mem_fault_nowait && pfn == KVM_PFN_ERR_FAULT) {
> > > + vcpu->run->exit_reason = KVM_EXIT_MEMORY_FAULT;
> > > + vcpu->run->memory_fault.gpa = gfn << PAGE_SHIFT;
> > > + vcpu->run->memory_fault.size = vma_pagesize;
> > > + return -EFAULT;
> >
> > We really don't want to get out to userspace with EFAULT. Instead, we
> > should get out to userspace with 0 as the return code to indicate a
> > 'normal' / expected exit.
> >
> > That will require a bit of redefinition on user_mem_abort()'s return
> > values:
> >
> > - < 0, return to userspace with an error
> > - 0, return to userspace for a 'normal' exit
> > - 1, resume the guest
>
> Ok, easy enough: do you want that patch sent separately or as part
> of the next version of this series?
Roll it into the next spin of the series. Splitting off patches (as asked
in patch 1) is only useful if there's a bugfix or some other reason for
inclusion ahead of the entire series.
--
Thanks,
Oliver
next prev parent reply other threads:[~2023-02-15 23:38 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-15 1:16 [PATCH 0/8] Add memory fault exits to avoid slow GUP Anish Moorthy
2023-02-15 1:16 ` [PATCH 1/8] selftests/kvm: Fix bug in how demand_paging_test calculates paging rate Anish Moorthy
2023-02-15 7:27 ` Oliver Upton
2023-02-15 16:44 ` Sean Christopherson
2023-02-15 18:05 ` Anish Moorthy
2023-02-15 1:16 ` [PATCH 2/8] selftests/kvm: Allow many vcpus per UFFD in demand paging test Anish Moorthy
2023-02-15 1:16 ` [PATCH 3/8] selftests/kvm: Switch demand paging uffd readers to epoll Anish Moorthy
2023-02-15 1:16 ` [PATCH 4/8] kvm: Allow hva_pfn_fast to resolve read-only faults Anish Moorthy
2023-02-15 9:01 ` Oliver Upton
2023-02-15 17:03 ` Sean Christopherson
2023-02-15 18:19 ` Anish Moorthy
2023-02-15 1:16 ` [PATCH 5/8] kvm: Add cap/kvm_run field for memory fault exits Anish Moorthy
2023-02-15 8:41 ` Marc Zyngier
2023-02-15 17:07 ` Sean Christopherson
2023-02-16 18:53 ` Anish Moorthy
2023-02-16 21:38 ` Sean Christopherson
2023-02-17 19:14 ` Anish Moorthy
2023-02-17 20:33 ` Sean Christopherson
2023-02-23 1:16 ` Anish Moorthy
2023-02-23 20:55 ` Sean Christopherson
2023-02-23 23:03 ` Anish Moorthy
2023-02-24 0:01 ` Sean Christopherson
2023-02-17 20:47 ` Sean Christopherson
2023-02-15 8:59 ` Oliver Upton
2023-02-15 1:16 ` [PATCH 6/8] kvm/x86: Add mem fault exit on EPT violations Anish Moorthy
2023-02-15 17:23 ` Sean Christopherson
2023-02-16 22:55 ` Peter Xu
2023-02-23 0:35 ` Anish Moorthy
2023-02-23 20:11 ` Sean Christopherson
2023-02-15 1:16 ` [PATCH 7/8] kvm/arm64: Implement KVM_CAP_MEM_FAULT_NOWAIT for arm64 Anish Moorthy
2023-02-15 18:24 ` Oliver Upton
2023-02-15 23:28 ` Anish Moorthy
2023-02-15 23:37 ` Oliver Upton [this message]
2023-02-15 1:16 ` [PATCH 8/8] selftests/kvm: Handle mem fault exits in demand paging test Anish Moorthy
2023-02-15 1:46 ` [PATCH 0/8] Add memory fault exits to avoid slow GUP James Houghton
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