From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Marcelo Tosatti <mtosatti@redhat.com>,
qemu-devel@nongnu.org, Igor Mammedov <imammedo@redhat.com>
Subject: Re: [PATCH v6 13/19] i386: prefer system KVM_GET_SUPPORTED_HV_CPUID ioctl over vCPU's one
Date: Wed, 26 May 2021 17:56:52 +0100 [thread overview]
Message-ID: <YK591Ge2KV+betiE@redhat.com> (raw)
In-Reply-To: <20210526164625.ci5xou7ikuiqkrpz@habkost.net>
On Wed, May 26, 2021 at 12:46:25PM -0400, Eduardo Habkost wrote:
> On Mon, May 24, 2021 at 02:08:26PM +0200, Vitaly Kuznetsov wrote:
> [...]
> > >> @@ -980,7 +989,7 @@ static struct kvm_cpuid2 *get_supported_hv_cpuid(CPUState *cs)
> > >> * information early, just check for the capability and set the bit
> > >> * manually.
> > >> */
> > >> - if (kvm_check_extension(cs->kvm_state,
> > >> + if (!do_sys_ioctl && kvm_check_extension(cs->kvm_state,
> > >> KVM_CAP_HYPERV_ENLIGHTENED_VMCS) > 0) {
> > >
> > > Oh, this conditional replaces the comment I suggested in patch
> > > 10/19. It makes it obvious that the hack can be deleted if we
> > > remove support for the VCPU ioctl.
> > >
> > > So, when exactly will we be able to delete the VCPU ioctl code
> > > and support only the system ioctl?
> >
> > When QEMU drops support for kernels < 5.11? Note, current RHEL8 already
> > supports system version so we're talking about upstream kernels/Ubuntu
> > LTS/...
> >
> > I remember there was a list of supported kernels for QEMU somewhere but
> > don't seem to be able to find it quickly, could you maybe point me in
> > the right direction?
>
> The KVM-specific kernel requirement is documented here:
> https://qemu-project.gitlab.io/qemu/system/target-i386.html?highlight=kvm#os-requirements
>
> I took a while to find it. Maybe we should have a more visible
> "runtime requirements" section in the docs, or it should be
> moved to the supported build platforms section.
>
> We have a clear policy on supported build platforms
> [https://qemu-project.gitlab.io/qemu/system/build-platforms.html],
> but not a clear policy for KVM kernel dependencies.
While it says "supported build platforms", that was implicitly
assumed to also refer to "runtime platforms". We should just
rename it to "supported-platforms.html" to make it more obvious.
Thus, the minimum KVM kernel version we need follows the same rules.
Look at whatever is the oldest kernel across the distros we target.
Regards,
Daniel
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next prev parent reply other threads:[~2021-05-26 16:59 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-22 16:11 [PATCH v6 00/19] i386: KVM: expand Hyper-V features early Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 01/19] i386: keep hyperv_vendor string up-to-date Vitaly Kuznetsov
2021-04-30 23:07 ` Eduardo Habkost
2021-06-02 11:41 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 02/19] i386: invert hyperv_spinlock_attempts setting logic with hv_passthrough Vitaly Kuznetsov
2021-04-30 23:09 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 03/19] i386: always fill Hyper-V CPUID feature leaves from X86CPU data Vitaly Kuznetsov
2021-04-30 23:15 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 04/19] i386: stop using env->features[] for filling Hyper-V CPUIDs Vitaly Kuznetsov
2021-05-01 0:34 ` Eduardo Habkost
2021-05-20 19:49 ` Eduardo Habkost
2021-05-21 7:54 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 05/19] i386: introduce hyperv_feature_supported() Vitaly Kuznetsov
2021-05-20 19:53 ` Eduardo Habkost
2021-05-21 7:57 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 06/19] i386: introduce hv_cpuid_get_host() Vitaly Kuznetsov
2021-05-20 20:01 ` Eduardo Habkost
2021-05-21 7:57 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 07/19] i386: drop FEAT_HYPERV feature leaves Vitaly Kuznetsov
2021-05-20 20:13 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 08/19] i386: introduce hv_cpuid_cache Vitaly Kuznetsov
2021-05-20 20:16 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 09/19] i386: split hyperv_handle_properties() into hyperv_expand_features()/hyperv_fill_cpuids() Vitaly Kuznetsov
2021-05-20 21:34 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 10/19] i386: move eVMCS enablement to hyperv_init_vcpu() Vitaly Kuznetsov
2021-05-21 21:20 ` Eduardo Habkost
2021-05-24 12:00 ` Vitaly Kuznetsov
2021-05-26 16:35 ` Eduardo Habkost
2021-05-27 7:27 ` Vitaly Kuznetsov
2021-05-27 19:16 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 11/19] i386: switch hyperv_expand_features() to using error_setg() Vitaly Kuznetsov
2021-05-21 21:37 ` Eduardo Habkost
2021-05-24 12:05 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 12/19] i386: adjust the expected KVM_GET_SUPPORTED_HV_CPUID array size Vitaly Kuznetsov
2021-05-21 21:37 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 13/19] i386: prefer system KVM_GET_SUPPORTED_HV_CPUID ioctl over vCPU's one Vitaly Kuznetsov
2021-05-21 21:42 ` Eduardo Habkost
2021-05-24 12:08 ` Vitaly Kuznetsov
2021-05-26 16:46 ` Eduardo Habkost
2021-05-26 16:56 ` Daniel P. Berrangé [this message]
2021-04-22 16:11 ` [PATCH v6 14/19] i386: use global kvm_state in hyperv_enabled() check Vitaly Kuznetsov
2021-05-21 21:42 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 15/19] i386: expand Hyper-V features during CPU feature expansion time Vitaly Kuznetsov
2021-05-21 21:45 ` Eduardo Habkost
2021-05-24 12:13 ` Vitaly Kuznetsov
2021-05-26 16:57 ` Eduardo Habkost
2021-05-27 7:29 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 16/19] i386: kill off hv_cpuid_check_and_set() Vitaly Kuznetsov
2021-05-21 21:56 ` Eduardo Habkost
2021-05-24 12:13 ` Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 17/19] i386: HV_HYPERCALL_AVAILABLE privilege bit is always needed Vitaly Kuznetsov
2021-05-21 22:06 ` Eduardo Habkost
2021-05-24 12:22 ` Vitaly Kuznetsov
2021-05-26 17:05 ` Eduardo Habkost
2021-05-27 7:37 ` Vitaly Kuznetsov
2021-05-27 19:34 ` Eduardo Habkost
2021-04-22 16:11 ` [PATCH v6 18/19] i386: Hyper-V SynIC requires POST_MESSAGES/SIGNAL_EVENTS priviliges Vitaly Kuznetsov
2021-04-22 16:11 ` [PATCH v6 19/19] qtest/hyperv: Introduce a simple hyper-v test Vitaly Kuznetsov
2021-05-26 20:20 ` [PATCH v6 00/19] i386: KVM: expand Hyper-V features early Eduardo Habkost
2021-05-27 7:39 ` Vitaly Kuznetsov
2021-05-27 19:35 ` Eduardo Habkost
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