From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Peter Xu <peterx@redhat.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Paul Mackerras" <paulus@ozlabs.org>,
"Christian Borntraeger" <borntraeger@de.ibm.com>,
"Janosch Frank" <frankja@linux.ibm.com>,
"David Hildenbrand" <david@redhat.com>,
"Cornelia Huck" <cohuck@redhat.com>,
"Vitaly Kuznetsov" <vkuznets@redhat.com>,
"Wanpeng Li" <wanpengli@tencent.com>,
"Jim Mattson" <jmattson@google.com>,
"Joerg Roedel" <joro@8bytes.org>, "Marc Zyngier" <maz@kernel.org>,
"James Morse" <james.morse@arm.com>,
"Julien Thierry" <julien.thierry.kdev@gmail.com>,
"Suzuki K Poulose" <suzuki.poulose@arm.com>,
linux-mips@vger.kernel.org, kvm@vger.kernel.org,
kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
"Christoffer Dall" <christoffer.dall@arm.com>,
"Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: Re: [PATCH v5 14/19] KVM: Clean up local variable usage in __kvm_set_memory_region()
Date: Thu, 6 Feb 2020 11:22:30 -0800 [thread overview]
Message-ID: <20200206192230.GE13067@linux.intel.com> (raw)
In-Reply-To: <20200206190641.GA700495@xz-x1>
On Thu, Feb 06, 2020 at 02:06:41PM -0500, Peter Xu wrote:
> On Tue, Jan 21, 2020 at 02:31:52PM -0800, Sean Christopherson wrote:
>
> [...]
>
> > @@ -1101,52 +1099,55 @@ int __kvm_set_memory_region(struct kvm *kvm,
> > if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
> > return -EINVAL;
> >
> > - slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
> > - base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
> > - npages = mem->memory_size >> PAGE_SHIFT;
> > -
> > - if (npages > KVM_MEM_MAX_NR_PAGES)
> > - return -EINVAL;
> > -
> > /*
> > * Make a full copy of the old memslot, the pointer will become stale
> > * when the memslots are re-sorted by update_memslots().
> > */
> > - old = *slot;
> > + tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id);
> > + old = *tmp;
> > + tmp = NULL;
>
> Shall we keep this chunk to the patch where it will be used? Other
> than that, it looks good to me.
I assume you're talking about doing this instead of using @tmp?
old = *id_to_memslot(__kvm_memslots(kvm, as_id), id);
It's obviously possible, but I really like resulting diff for
__kvm_set_memory_region() in "KVM: Terminate memslot walks via used_slots"
when tmp is used.
@@ -1104,8 +1203,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
* when the memslots are re-sorted by update_memslots().
*/
tmp = id_to_memslot(__kvm_memslots(kvm, as_id), id);
- old = *tmp;
- tmp = NULL;
+ if (tmp) {
+ old = *tmp;
+ tmp = NULL;
+ } else {
+ memset(&old, 0, sizeof(old));
+ old.id = id;
+ }
next prev parent reply other threads:[~2020-02-06 19:22 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-21 22:31 [PATCH v5 00/19] KVM: Dynamically size memslot arrays Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 01/19] KVM: x86: Allocate new rmap and large page tracking when moving memslot Sean Christopherson
2020-02-05 21:49 ` Peter Xu
2020-02-05 23:55 ` Sean Christopherson
2020-02-06 2:00 ` Peter Xu
2020-02-06 2:17 ` Sean Christopherson
2020-02-06 2:58 ` Peter Xu
2020-02-06 5:05 ` Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 02/19] KVM: Reinstall old memslots if arch preparation fails Sean Christopherson
2020-02-05 22:08 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 03/19] KVM: Don't free new memslot if allocation of said memslot fails Sean Christopherson
2020-02-05 22:28 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 04/19] KVM: PPC: Move memslot memory allocation into prepare_memory_region() Sean Christopherson
2020-02-05 22:41 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 05/19] KVM: x86: Allocate memslot resources during prepare_memory_region() Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 06/19] KVM: Drop kvm_arch_create_memslot() Sean Christopherson
2020-02-05 22:45 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 07/19] KVM: Explicitly free allocated-but-unused dirty bitmap Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 08/19] KVM: Refactor error handling for setting memory region Sean Christopherson
2020-02-05 22:48 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 09/19] KVM: Move setting of memslot into helper routine Sean Christopherson
2020-02-06 16:26 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 10/19] KVM: Drop "const" attribute from old memslot in commit_memory_region() Sean Christopherson
2020-02-06 16:26 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 11/19] KVM: x86: Free arrays for old memslot when moving memslot's base gfn Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 12/19] KVM: Move memslot deletion to helper function Sean Christopherson
2020-02-06 16:14 ` Peter Xu
2020-02-06 16:28 ` Sean Christopherson
2020-02-06 16:51 ` Peter Xu
2020-02-07 17:59 ` Sean Christopherson
2020-02-07 18:07 ` Sean Christopherson
2020-02-07 18:17 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 13/19] KVM: Simplify kvm_free_memslot() and all its descendents Sean Christopherson
2020-02-06 16:29 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 14/19] KVM: Clean up local variable usage in __kvm_set_memory_region() Sean Christopherson
2020-02-06 19:06 ` Peter Xu
2020-02-06 19:22 ` Sean Christopherson [this message]
2020-02-06 19:36 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 15/19] KVM: Provide common implementation for generic dirty log functions Sean Christopherson
2020-02-06 20:02 ` Peter Xu
2020-02-06 21:21 ` Sean Christopherson
2020-02-06 21:41 ` Peter Xu
2020-02-07 19:45 ` Sean Christopherson
2020-02-08 0:18 ` Peter Xu
2020-02-08 0:42 ` Sean Christopherson
2020-02-08 0:53 ` Peter Xu
2020-02-08 1:29 ` Sean Christopherson
2020-02-17 15:39 ` Vitaly Kuznetsov
2020-02-18 17:10 ` Sean Christopherson
2020-02-17 15:35 ` Vitaly Kuznetsov
2020-02-06 21:24 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 16/19] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log() Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 17/19] KVM: Terminate memslot walks via used_slots Sean Christopherson
2020-02-06 21:09 ` Peter Xu
2020-02-07 18:33 ` Sean Christopherson
2020-02-07 20:39 ` Peter Xu
2020-02-07 21:10 ` Sean Christopherson
2020-02-07 21:46 ` Peter Xu
2020-02-07 22:03 ` Sean Christopherson
2020-02-07 22:24 ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 18/19] KVM: Dynamically size memslot array based on number of used slots Sean Christopherson
2020-02-06 22:12 ` Peter Xu
2020-02-07 15:38 ` Sean Christopherson
2020-02-07 16:05 ` Peter Xu
2020-02-07 16:15 ` Sean Christopherson
2020-02-07 16:37 ` Peter Xu
2020-02-07 16:47 ` Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 19/19] KVM: selftests: Add test for KVM_SET_USER_MEMORY_REGION Sean Christopherson
2020-02-06 22:30 ` Peter Xu
2020-02-06 23:11 ` Sean Christopherson
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