* [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() @ 2023-03-16 15:45 Shameer Kolothum 2023-03-16 17:02 ` Sean Christopherson 0 siblings, 1 reply; 6+ messages in thread From: Shameer Kolothum @ 2023-03-16 15:45 UTC (permalink / raw) To: linux-kernel, kvm; +Cc: gshan, maz The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. Fixes: cf87ac739e48 ("KVM: x86: Introduce KVM_REQ_DIRTY_RING_SOFT_FULL") Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> --- include/linux/kvm_dirty_ring.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/include/linux/kvm_dirty_ring.h b/include/linux/kvm_dirty_ring.h index 4862c98d80d3..a00301059da5 100644 --- a/include/linux/kvm_dirty_ring.h +++ b/include/linux/kvm_dirty_ring.h @@ -69,6 +69,11 @@ static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring) { } +static inline bool kvm_dirty_ring_check_request(struct kvm_vcpu *vcpu) +{ + return false; +} + #else /* CONFIG_HAVE_KVM_DIRTY_RING */ int kvm_cpu_dirty_log_size(void); -- 2.34.1 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() 2023-03-16 15:45 [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() Shameer Kolothum @ 2023-03-16 17:02 ` Sean Christopherson 2023-03-16 19:39 ` Shameerali Kolothum Thodi 0 siblings, 1 reply; 6+ messages in thread From: Sean Christopherson @ 2023-03-16 17:02 UTC (permalink / raw) To: Shameer Kolothum; +Cc: linux-kernel, kvm, gshan, maz On Thu, Mar 16, 2023, Shameer Kolothum wrote: > The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. No stub is needed. kvm_dirty_ring_check_request() isn't called from common code, and should not (and isn't unless I'm missing something) be called from arch code unless CONFIG_HAVE_KVM_DIRTY_RING=y. x86 and arm64 are the only users, and they both select HAVE_KVM_DIRTY_RING unconditionally when KVM is enabled. ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() 2023-03-16 17:02 ` Sean Christopherson @ 2023-03-16 19:39 ` Shameerali Kolothum Thodi 2023-03-16 19:57 ` Sean Christopherson 0 siblings, 1 reply; 6+ messages in thread From: Shameerali Kolothum Thodi @ 2023-03-16 19:39 UTC (permalink / raw) To: Sean Christopherson; +Cc: linux-kernel, kvm, gshan, maz > -----Original Message----- > From: Sean Christopherson [mailto:seanjc@google.com] > Sent: 16 March 2023 17:02 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> > Cc: linux-kernel@vger.kernel.org; kvm@vger.kernel.org; gshan@redhat.com; > maz@kernel.org > Subject: Re: [PATCH] KVM: Add the missing stub function for > kvm_dirty_ring_check_request() > > On Thu, Mar 16, 2023, Shameer Kolothum wrote: > > The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. > > No stub is needed. kvm_dirty_ring_check_request() isn't called from > common code, > and should not (and isn't unless I'm missing something) be called from arch > code > unless CONFIG_HAVE_KVM_DIRTY_RING=y. > > x86 and arm64 are the only users, and they both select > HAVE_KVM_DIRTY_RING > unconditionally when KVM is enabled. Yes, it is at present not called from anywhere other than x86 and arm64. But I still think since it is a common helper, better to have a stub. Thanks, Shameer ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() 2023-03-16 19:39 ` Shameerali Kolothum Thodi @ 2023-03-16 19:57 ` Sean Christopherson 2023-03-16 20:02 ` Shameerali Kolothum Thodi 0 siblings, 1 reply; 6+ messages in thread From: Sean Christopherson @ 2023-03-16 19:57 UTC (permalink / raw) To: Shameerali Kolothum Thodi; +Cc: linux-kernel, kvm, gshan, maz On Thu, Mar 16, 2023, Shameerali Kolothum Thodi wrote: > > From: Sean Christopherson [mailto:seanjc@google.com] > > On Thu, Mar 16, 2023, Shameer Kolothum wrote: > > > The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. > > > > No stub is needed. kvm_dirty_ring_check_request() isn't called from > > common code, > > and should not (and isn't unless I'm missing something) be called from arch > > code > > unless CONFIG_HAVE_KVM_DIRTY_RING=y. > > > > x86 and arm64 are the only users, and they both select > > HAVE_KVM_DIRTY_RING > > unconditionally when KVM is enabled. > > Yes, it is at present not called from anywhere other than x86 and arm64. > But I still think since it is a common helper, better to have a stub. Why? It buys us nothing other than dead code, and even worse it could let a bug that would otherwise be caught during build time escape to run time. ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() 2023-03-16 19:57 ` Sean Christopherson @ 2023-03-16 20:02 ` Shameerali Kolothum Thodi 2023-03-17 0:18 ` Sean Christopherson 0 siblings, 1 reply; 6+ messages in thread From: Shameerali Kolothum Thodi @ 2023-03-16 20:02 UTC (permalink / raw) To: Sean Christopherson; +Cc: linux-kernel, kvm, gshan, maz > -----Original Message----- > From: Sean Christopherson [mailto:seanjc@google.com] > Sent: 16 March 2023 19:57 > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com> > Cc: linux-kernel@vger.kernel.org; kvm@vger.kernel.org; gshan@redhat.com; > maz@kernel.org > Subject: Re: [PATCH] KVM: Add the missing stub function for > kvm_dirty_ring_check_request() > > On Thu, Mar 16, 2023, Shameerali Kolothum Thodi wrote: > > > From: Sean Christopherson [mailto:seanjc@google.com] On Thu, Mar 16, > > > 2023, Shameer Kolothum wrote: > > > > The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. > > > > > > No stub is needed. kvm_dirty_ring_check_request() isn't called from > > > common code, and should not (and isn't unless I'm missing something) > > > be called from arch code unless CONFIG_HAVE_KVM_DIRTY_RING=y. > > > > > > x86 and arm64 are the only users, and they both select > > > HAVE_KVM_DIRTY_RING unconditionally when KVM is enabled. > > > > Yes, it is at present not called from anywhere other than x86 and arm64. > > But I still think since it is a common helper, better to have a stub. > > Why? It buys us nothing other than dead code, and even worse it could let > a bug that would otherwise be caught during build time escape to run time. Agree, it buys nothing now:) It just came up while I was playing with a custom build without HAVE_KVM_DIRTY_RING. Since all other functions there has a stub just thought it would make it easier for future common usage. We could very well leave it till that comes up as well. Thanks, Shameer ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() 2023-03-16 20:02 ` Shameerali Kolothum Thodi @ 2023-03-17 0:18 ` Sean Christopherson 0 siblings, 0 replies; 6+ messages in thread From: Sean Christopherson @ 2023-03-17 0:18 UTC (permalink / raw) To: Shameerali Kolothum Thodi; +Cc: linux-kernel, kvm, gshan, maz On Thu, Mar 16, 2023, Shameerali Kolothum Thodi wrote: > > From: Sean Christopherson [mailto:seanjc@google.com] > > On Thu, Mar 16, 2023, Shameerali Kolothum Thodi wrote: > > > > From: Sean Christopherson [mailto:seanjc@google.com] On Thu, Mar 16, > > > > 2023, Shameer Kolothum wrote: > > > > > The stub for !CONFIG_HAVE_KVM_DIRTY_RING case is missing. > > > > > > > > No stub is needed. kvm_dirty_ring_check_request() isn't called from > > > > common code, and should not (and isn't unless I'm missing something) > > > > be called from arch code unless CONFIG_HAVE_KVM_DIRTY_RING=y. > > > > > > > > x86 and arm64 are the only users, and they both select > > > > HAVE_KVM_DIRTY_RING unconditionally when KVM is enabled. > > > > > > Yes, it is at present not called from anywhere other than x86 and arm64. > > > But I still think since it is a common helper, better to have a stub. > > > > Why? It buys us nothing other than dead code, and even worse it could let > > a bug that would otherwise be caught during build time escape to run time. > > Agree, it buys nothing now:) It just came up while I was playing with a custom > build without HAVE_KVM_DIRTY_RING. Since all other functions there has a stub > just thought it would make it easier for future common usage. We could very well > leave it till that comes up as well. Stubs are typically only added when they are strictly necessary. Providing a stub would make things "easier" in the sense that it could theoretically avoid a build error, but as above, in many cases we _want_ build errors when new code behaves in a way that diverges from what's expected/established. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-03-17 0:18 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2023-03-16 15:45 [PATCH] KVM: Add the missing stub function for kvm_dirty_ring_check_request() Shameer Kolothum 2023-03-16 17:02 ` Sean Christopherson 2023-03-16 19:39 ` Shameerali Kolothum Thodi 2023-03-16 19:57 ` Sean Christopherson 2023-03-16 20:02 ` Shameerali Kolothum Thodi 2023-03-17 0:18 ` Sean Christopherson
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