| Message ID | 20231004171102.2073141-1-paul@xen.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: xen: ignore the VCPU_SSHOTTMR_future flag | expand |
On Wed, 2023-10-04 at 17:11 +0000, Paul Durrant wrote: > From: Paul Durrant <pdurrant@amazon.com> > > Upstream Xen now ignores this flag [1], since the only guest kernel ever to > use it was buggy. By ignoring the flag the guest will always get a callback > if it sets a negative timeout which upstream Xen has determined not to > cause problems for any guest setting the flag. > > [1] https://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=19c6cbd909 > > Signed-off-by: Paul Durrant <pdurrant@amazon.com> nit: I think the commit title should probably be 'KVM: x86:' and then mention Xen somewhere in the rest of the line? Reviewed-by: David Woodhouse <dwmw@amazon.co.uk> > --- > Cc: David Woodhouse <dwmw2@infradead.org> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Borislav Petkov <bp@alien8.de> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: x86@kernel.org > --- > arch/x86/kvm/xen.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c > index 40edf4d1974c..8f1d46df0f3b 100644 > --- a/arch/x86/kvm/xen.c > +++ b/arch/x86/kvm/xen.c > @@ -1374,12 +1374,8 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd, > return true; > } > > + /* A delta <= 0 results in an immediate callback, which is what we want */ > delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm); > - if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) { > - *r = -ETIME; > - return true; > - } > - > kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta); > *r = 0; > return true;
On Wed, Oct 04, 2023, David Woodhouse wrote: > On Wed, 2023-10-04 at 17:11 +0000, Paul Durrant wrote: > nit: I think the commit title should probably be 'KVM: x86:' and then > mention Xen somewhere in the rest of the line? I would also be ok if we start doing "KVM: x86/xen:", because it seems like y'all are sending enough Xen specific changes that differentiating would be useful.
On 04/10/2023 18:34, Sean Christopherson wrote: > On Wed, Oct 04, 2023, David Woodhouse wrote: >> On Wed, 2023-10-04 at 17:11 +0000, Paul Durrant wrote: >> nit: I think the commit title should probably be 'KVM: x86:' and then >> mention Xen somewhere in the rest of the line? > > I would also be ok if we start doing "KVM: x86/xen:", because it seems like y'all > are sending enough Xen specific changes that differentiating would be useful. Ok, I'll send a v2 with an amended subject line. Paul
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 40edf4d1974c..8f1d46df0f3b 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -1374,12 +1374,8 @@ static bool kvm_xen_hcall_vcpu_op(struct kvm_vcpu *vcpu, bool longmode, int cmd, return true; } + /* A delta <= 0 results in an immediate callback, which is what we want */ delta = oneshot.timeout_abs_ns - get_kvmclock_ns(vcpu->kvm); - if ((oneshot.flags & VCPU_SSHOTTMR_future) && delta < 0) { - *r = -ETIME; - return true; - } - kvm_xen_start_timer(vcpu, oneshot.timeout_abs_ns, delta); *r = 0; return true;