From: Paul Mackerras <paulus@ozlabs.org>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH v2 03/16] KVM: PPC: Book3S HV: XIVE: introduce a new capability KVM_CAP_PPC_IRQ_XIVE
Date: Mon, 25 Feb 2019 15:35:51 +1100 [thread overview]
Message-ID: <20190225043551.GA20501@blackberry> (raw)
In-Reply-To: <20190222112840.25000-4-clg@kaod.org>
On Fri, Feb 22, 2019 at 12:28:27PM +0100, Cédric Le Goater wrote:
> The user interface exposes a new capability to let QEMU connect the
> vCPU to the XIVE KVM device if required. The capability is only
> advertised on a PowerNV Hypervisor as support for nested guests
> (pseries KVM Hypervisor) is not yet available.
If a bisection happened to land on this commit, we would have KVM
saying it had the ability to support guests using XIVE natively, but
it wouldn't actually work since we don't have all the code that is in
the following patches.
Thus, in order to avoid breaking bisection, you should either add the
capability now but have it always return false until the rest of the
code is in place, or else defer the addition of the capability until
the end of the patch series.
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 8c69af10f91d..a38a643a24dd 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -570,6 +570,12 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_PPC_GET_CPU_CHAR:
> r = 1;
> break;
> +#ifdef CONFIG_KVM_XIVE
> + case KVM_CAP_PPC_IRQ_XIVE:
> + /* only for PowerNV */
> + r = !!cpu_has_feature(CPU_FTR_HVMODE);
Shouldn't this be r = xive_enabled() && !!cpu_has_feature(CPU_FTR_HVMODE)
(or alternatively r = xics_on_xive(), though that would be confusing
to the reader)?
As it stands this would report true on POWER8, unless I'm missing
something.
Paul.
WARNING: multiple messages have this Message-ID (diff)
From: Paul Mackerras <paulus@ozlabs.org>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org,
David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [PATCH v2 03/16] KVM: PPC: Book3S HV: XIVE: introduce a new capability KVM_CAP_PPC_IRQ_XIVE
Date: Mon, 25 Feb 2019 04:35:51 +0000 [thread overview]
Message-ID: <20190225043551.GA20501@blackberry> (raw)
In-Reply-To: <20190222112840.25000-4-clg@kaod.org>
On Fri, Feb 22, 2019 at 12:28:27PM +0100, Cédric Le Goater wrote:
> The user interface exposes a new capability to let QEMU connect the
> vCPU to the XIVE KVM device if required. The capability is only
> advertised on a PowerNV Hypervisor as support for nested guests
> (pseries KVM Hypervisor) is not yet available.
If a bisection happened to land on this commit, we would have KVM
saying it had the ability to support guests using XIVE natively, but
it wouldn't actually work since we don't have all the code that is in
the following patches.
Thus, in order to avoid breaking bisection, you should either add the
capability now but have it always return false until the rest of the
code is in place, or else defer the addition of the capability until
the end of the patch series.
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 8c69af10f91d..a38a643a24dd 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -570,6 +570,12 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
> case KVM_CAP_PPC_GET_CPU_CHAR:
> r = 1;
> break;
> +#ifdef CONFIG_KVM_XIVE
> + case KVM_CAP_PPC_IRQ_XIVE:
> + /* only for PowerNV */
> + r = !!cpu_has_feature(CPU_FTR_HVMODE);
Shouldn't this be r = xive_enabled() && !!cpu_has_feature(CPU_FTR_HVMODE)
(or alternatively r = xics_on_xive(), though that would be confusing
to the reader)?
As it stands this would report true on POWER8, unless I'm missing
something.
Paul.
next prev parent reply other threads:[~2019-02-25 4:35 UTC|newest]
Thread overview: 142+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 11:28 [PATCH v2 00/16] KVM: PPC: Book3S HV: add XIVE native exploitation mode Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 01/16] powerpc/xive: add OPAL extensions for the XIVE native exploitation support Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-24 23:42 ` David Gibson
2019-02-24 23:42 ` David Gibson
2019-02-25 3:50 ` Michael Ellerman
2019-02-25 3:50 ` Michael Ellerman
2019-02-25 10:11 ` Cédric Le Goater
2019-02-25 10:11 ` Cédric Le Goater
2019-02-26 4:21 ` David Gibson
2019-02-26 4:21 ` David Gibson
2019-03-12 18:25 ` Cédric Le Goater
2019-03-12 18:25 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 02/16] KVM: PPC: Book3S HV: add a new KVM device for the XIVE native exploitation mode Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 0:08 ` David Gibson
2019-02-25 0:08 ` David Gibson
2019-03-12 11:14 ` Cédric Le Goater
2019-03-12 11:14 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 03/16] KVM: PPC: Book3S HV: XIVE: introduce a new capability KVM_CAP_PPC_IRQ_XIVE Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 0:35 ` David Gibson
2019-02-25 0:35 ` David Gibson
2019-02-25 4:59 ` Paul Mackerras
2019-02-25 4:59 ` Paul Mackerras
2019-03-12 14:10 ` Cédric Le Goater
2019-03-12 14:10 ` Cédric Le Goater
2019-03-12 14:03 ` Cédric Le Goater
2019-03-12 14:03 ` Cédric Le Goater
2019-03-13 4:05 ` David Gibson
2019-03-13 4:05 ` David Gibson
2019-02-25 4:35 ` Paul Mackerras [this message]
2019-02-25 4:35 ` Paul Mackerras
2019-03-13 8:34 ` Cédric Le Goater
2019-03-13 8:34 ` Cédric Le Goater
2019-03-14 2:29 ` David Gibson
2019-03-14 2:29 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 04/16] KVM: PPC: Book3S HV: XIVE: add a control to initialize a source Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:10 ` David Gibson
2019-02-25 2:10 ` David Gibson
2019-02-26 4:25 ` Paul Mackerras
2019-02-26 4:25 ` Paul Mackerras
2019-02-26 23:20 ` David Gibson
2019-02-26 23:20 ` David Gibson
2019-03-12 15:19 ` Cédric Le Goater
2019-03-12 15:19 ` Cédric Le Goater
2019-03-14 2:15 ` David Gibson
2019-03-14 2:15 ` David Gibson
2019-02-25 5:30 ` Paul Mackerras
2019-02-25 5:30 ` Paul Mackerras
2019-02-22 11:28 ` [PATCH v2 05/16] KVM: PPC: Book3S HV: XIVE: add a control to configure " Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:21 ` David Gibson
2019-02-25 2:21 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 06/16] KVM: PPC: Book3S HV: XIVE: add controls for the EQ configuration Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:39 ` David Gibson
2019-02-25 2:39 ` David Gibson
2019-03-12 17:00 ` Cédric Le Goater
2019-03-12 17:00 ` Cédric Le Goater
2019-03-13 4:03 ` David Gibson
2019-03-13 4:03 ` David Gibson
2019-03-13 8:46 ` Cédric Le Goater
2019-03-13 8:46 ` Cédric Le Goater
2019-03-14 3:29 ` David Gibson
2019-03-14 3:29 ` David Gibson
2019-02-26 5:24 ` Paul Mackerras
2019-02-26 5:24 ` Paul Mackerras
2019-03-13 9:40 ` Cédric Le Goater
2019-03-13 9:40 ` Cédric Le Goater
2019-03-14 2:32 ` David Gibson
2019-03-14 2:32 ` David Gibson
2019-03-14 7:11 ` Cédric Le Goater
2019-03-14 7:11 ` Cédric Le Goater
2019-03-15 0:29 ` David Gibson
2019-03-15 0:29 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 07/16] KVM: PPC: Book3S HV: XIVE: add a global reset control Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:43 ` David Gibson
2019-02-25 2:43 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 08/16] KVM: PPC: Book3S HV: XIVE: add a control to sync the sources Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:45 ` David Gibson
2019-02-25 2:45 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 09/16] KVM: PPC: Book3S HV: XIVE: add a control to dirty the XIVE EQ pages Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 2:53 ` David Gibson
2019-02-25 2:53 ` David Gibson
2019-03-13 11:48 ` Cédric Le Goater
2019-03-13 11:48 ` Cédric Le Goater
2019-03-14 2:33 ` David Gibson
2019-03-14 2:33 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 10/16] KVM: PPC: Book3S HV: XIVE: add get/set accessors for the VP XIVE state Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 3:31 ` David Gibson
2019-02-25 3:31 ` David Gibson
2019-03-13 13:19 ` Cédric Le Goater
2019-03-13 13:19 ` Cédric Le Goater
2019-03-14 3:09 ` David Gibson
2019-03-14 3:09 ` David Gibson
2019-03-14 7:08 ` Cédric Le Goater
2019-03-14 7:08 ` Cédric Le Goater
2019-02-22 11:28 ` [PATCH v2 11/16] KVM: introduce a 'mmap' method for KVM devices Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 3:33 ` David Gibson
2019-02-25 3:33 ` David Gibson
2019-02-25 10:57 ` Cédric Le Goater
2019-02-25 10:57 ` Cédric Le Goater
2019-02-26 12:52 ` Paolo Bonzini
2019-02-26 12:52 ` Paolo Bonzini
2019-02-26 23:22 ` David Gibson
2019-02-26 23:22 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 12/16] KVM: PPC: Book3S HV: XIVE: add a TIMA mapping Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 3:42 ` David Gibson
2019-02-25 3:42 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 13/16] KVM: PPC: Book3S HV: XIVE: add a mapping for the source ESB pages Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 3:47 ` David Gibson
2019-02-25 3:47 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 14/16] KVM: PPC: Book3S HV: XIVE: add passthrough support Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 4:13 ` David Gibson
2019-02-25 4:13 ` David Gibson
2019-02-22 11:28 ` [PATCH v2 15/16] KVM: introduce a KVM_DESTROY_DEVICE ioctl Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 4:15 ` David Gibson
2019-02-25 4:15 ` David Gibson
2019-03-13 8:02 ` Cédric Le Goater
2019-03-13 8:02 ` Cédric Le Goater
2019-03-15 17:57 ` Paolo Bonzini
2019-03-15 17:57 ` Paolo Bonzini
2019-02-22 11:28 ` [PATCH v2 16/16] KVM: PPC: Book3S HV: XIVE: clear the vCPU interrupt presenters Cédric Le Goater
2019-02-22 11:28 ` Cédric Le Goater
2019-02-25 4:18 ` David Gibson
2019-02-25 4:18 ` David Gibson
2019-03-13 8:17 ` Cédric Le Goater
2019-03-13 8:17 ` Cédric Le Goater
2019-03-14 2:26 ` David Gibson
2019-03-14 2:26 ` David Gibson
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