Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-03-07 Thread Radim Krčmář
2018-03-05 11:29+0100, Vitaly Kuznetsov: > Vitaly Kuznetsov writes: > > > Devices which use level-triggered interrupts under Windows 2016 with > > Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV > > unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPI

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-03-05 Thread Vitaly Kuznetsov
Vitaly Kuznetsov writes: > Devices which use level-triggered interrupts under Windows 2016 with > Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV > unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPIC > version which has no EOI register so EOI never

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-12 Thread Paolo Bonzini
On 12/02/2018 12:30, Vitaly Kuznetsov wrote: >> - Radim's suggestion was to disable DIRECTED_EOI unconditionally but I'm not >> that radical :-) In theory, we may have multiple IOAPICs in userspace in >> future and DIRECTED_EOI can be leveraged. > > I sort of agree on this, especially consider

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-12 Thread Vitaly Kuznetsov
Peter Xu writes: > On Fri, Feb 09, 2018 at 02:01:33PM +0100, Vitaly Kuznetsov wrote: >> Devices which use level-triggered interrupts under Windows 2016 with >> Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV >> unconditionally. Our in-kernel IOAPIC implementation emulates

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-10 Thread Peter Xu
On Fri, Feb 09, 2018 at 02:01:33PM +0100, Vitaly Kuznetsov wrote: > Devices which use level-triggered interrupts under Windows 2016 with > Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV > unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPIC > version

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-09 Thread Vitaly Kuznetsov
Nikita Leshenko writes: > The patch looks correct, however I’m confused about why you consider > this to be a bug in the guest rather than a bug in KVM. > > The spec for x2APIC states: > "The support for Directed EOI capability can be detected by means of > bit 24 in the Local APIC Version Regist

Re: [PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-09 Thread Nikita Leshenko
The patch looks correct, however I’m confused about why you consider this to be a bug in the guest rather than a bug in KVM. The spec for x2APIC states: "The support for Directed EOI capability can be detected by means of bit 24 in the Local APIC Version Register” (Intel’s x2APIC spec, 2.5.1 Direc

[PATCH] KVM: lapic: stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use

2018-02-09 Thread Vitaly Kuznetsov
Devices which use level-triggered interrupts under Windows 2016 with Hyper-V role enabled don't work: Windows disables EOI broadcast in SPIV unconditionally. Our in-kernel IOAPIC implementation emulates an old IOAPIC version which has no EOI register so EOI never happens. The issue was discovered