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From: Daniel Axtens <dja@axtens.net>
To: Nicholas Piggin <npiggin@gmail.com>, kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Fabiano Rosas <farosas@linux.ibm.com>
Subject: Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
Date: Fri, 05 Mar 2021 15:50:59 +1100	[thread overview]
Message-ID: <87tupq8aq4.fsf@linkitivity.dja.id.au> (raw)
In-Reply-To: <1614383549.rxe6rxw7w8.astroid@bobo.none>

>> This 'if' is technically redundant but you mention a future patch warning
>> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
>> I get to that patch :)
>
> That's true. The warning is actually further down when we're setting up 
> the msr to run in guest mode. At this point the MSR I think comes from
> qemu (and arguably the guest setup code shouldn't need to know about HV
> specific MSR bits) so a warning here wouldn't be appropriate.
>
> I could remove the if, although the compiler might already do that.

Yes, I think the compiler is almost certainly going to remove that.

I'd probably not include the 'if' statement even though it probably gets
removed by the compiler but I think that's more a matter of taste than
anything else.

Kind regards,
Daniel

>
>> 
>> The patch seems sane to me, I agree that we don't want guests running with
>> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
>> sane so this is another sanity-enforcement in the same sort of vein.
>> 
>> All up:
>> Reviewed-by: Daniel Axtens <dja@axtens.net>
>
> Thanks,
> Nick

WARNING: multiple messages have this Message-ID (diff)
From: Daniel Axtens <dja@axtens.net>
To: Nicholas Piggin <npiggin@gmail.com>, kvm-ppc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org, Fabiano Rosas <farosas@linux.ibm.com>
Subject: Re: [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR
Date: Fri, 05 Mar 2021 04:50:59 +0000	[thread overview]
Message-ID: <87tupq8aq4.fsf@linkitivity.dja.id.au> (raw)
In-Reply-To: <1614383549.rxe6rxw7w8.astroid@bobo.none>

>> This 'if' is technically redundant but you mention a future patch warning
>> on !(msr & MSR_ME) so I'm holding off on any judgement about the 'if' until
>> I get to that patch :)
>
> That's true. The warning is actually further down when we're setting up 
> the msr to run in guest mode. At this point the MSR I think comes from
> qemu (and arguably the guest setup code shouldn't need to know about HV
> specific MSR bits) so a warning here wouldn't be appropriate.
>
> I could remove the if, although the compiler might already do that.

Yes, I think the compiler is almost certainly going to remove that.

I'd probably not include the 'if' statement even though it probably gets
removed by the compiler but I think that's more a matter of taste than
anything else.

Kind regards,
Daniel

>
>> 
>> The patch seems sane to me, I agree that we don't want guests running with
>> MSR_ME=0 and kvmppc_set_msr_hv already ensures that the transactional state is
>> sane so this is another sanity-enforcement in the same sort of vein.
>> 
>> All up:
>> Reviewed-by: Daniel Axtens <dja@axtens.net>
>
> Thanks,
> Nick

  reply	other threads:[~2021-03-05  4:51 UTC|newest]

Thread overview: 134+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-25 13:46 [PATCH v2 00/37] KVM: PPC: Book3S: C-ify the P9 entry/exit code Nicholas Piggin
2021-02-25 13:46 ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:01   ` Daniel Axtens
2021-02-26  5:01     ` Daniel Axtens
2021-02-26 23:50     ` Nicholas Piggin
2021-02-26 23:50       ` Nicholas Piggin
2021-03-05  4:45       ` Daniel Axtens
2021-03-05  4:45         ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 02/37] KVM: PPC: Book3S HV: Fix CONFIG_SPAPR_TCE_IOMMU=n default hcalls Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:21   ` Daniel Axtens
2021-02-26  5:21     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 03/37] powerpc/64s: Remove KVM handler support from CBE_RAS interrupts Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  5:44   ` Daniel Axtens
2021-02-26  5:44     ` Daniel Axtens
2021-02-26 23:51     ` Nicholas Piggin
2021-02-26 23:51       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 05/37] KVM: PPC: Book3S HV: Ensure MSR[ME] is always set in guest MSR Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26  6:06   ` Daniel Axtens
2021-02-26  6:06     ` Daniel Axtens
2021-02-26 23:55     ` Nicholas Piggin
2021-02-26 23:55       ` Nicholas Piggin
2021-03-05  4:50       ` Daniel Axtens [this message]
2021-03-05  4:50         ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 06/37] KVM: PPC: Book3S 64: move KVM interrupt entry to a common entry point Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  5:03   ` Daniel Axtens
2021-03-05  5:03     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 07/37] KVM: PPC: Book3S 64: Move GUEST_MODE_SKIP test into KVM Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  5:54   ` Daniel Axtens
2021-03-05  5:54     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  6:03   ` Daniel Axtens
2021-03-05  6:03     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 09/37] KVM: PPC: Book3S 64: Move hcall early register setup to KVM Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-05  6:48   ` Daniel Axtens
2021-03-05  6:48     ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 10/37] KVM: PPC: Book3S 64: Move interrupt " Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 11/37] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 12/37] KVM: PPC: Book3S 64: Minimise hcall handler calling convention differences Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 15:56   ` Fabiano Rosas
2021-02-26 15:56     ` Fabiano Rosas
2021-02-26 23:57     ` Nicholas Piggin
2021-02-26 23:57       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 14/37] KVM: PPC: Book3S HV P9: implement kvmppc_xive_pull_vcpu in C Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 15/37] KVM: PPC: Book3S HV P9: Move xive vcpu context management into kvmhv_p9_guest_entry Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 14:51   ` Cédric Le Goater
2021-02-25 14:51     ` Cédric Le Goater
2021-02-26 23:59     ` Nicholas Piggin
2021-02-26 23:59       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 17/37] KVM: PPC: Book3S HV P9: Move setting HDEC after switching to guest LPCR Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 16:38   ` Fabiano Rosas
2021-02-26 16:38     ` Fabiano Rosas
2021-02-26 23:59     ` Nicholas Piggin
2021-02-26 23:59       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 18/37] KVM: PPC: Book3S HV P9: Use large decrementer for HDEC Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 19/37] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 20/37] KVM: PPC: Book3S HV P9: Reduce mftb per guest entry/exit Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 21/37] powerpc: add set_dec_or_work API for safely updating decrementer Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 22/37] KVM: PPC: Book3S HV P9: Reduce irq_work vs guest decrementer races Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-26 22:37   ` Fabiano Rosas
2021-02-26 22:37     ` Fabiano Rosas
2021-02-27  0:21     ` Nicholas Piggin
2021-02-27  0:21       ` Nicholas Piggin
2021-02-27  0:55       ` Nicholas Piggin
2021-02-27  0:55         ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entry_p9 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 13:48   ` Fabiano Rosas
2021-03-02 13:48     ` [PATCH v2 24/37] KVM: PPC: Book3S HV P9: inline kvmhv_load_hv_regs_and_go into __kvmhv_vcpu_entr Fabiano Rosas
2021-02-25 13:46 ` [PATCH v2 25/37] KVM: PPC: Book3S HV P9: Read machine check registers while MSR[RI] is 0 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 26/37] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 27/37] KVM: PPC: Book3S HV P9: Move SPR loading after expiry time check Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 15:04   ` Fabiano Rosas
2021-03-02 15:04     ` Fabiano Rosas
2021-03-04 11:02     ` Nicholas Piggin
2021-03-04 11:02       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 29/37] KVM: PPC: Book3S HV P9: Switch to guest MMU context as late as possible Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-02 21:21   ` Fabiano Rosas
2021-03-02 21:21     ` Fabiano Rosas
2021-03-04 11:04     ` Nicholas Piggin
2021-03-04 11:04       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 31/37] KVM: PPC: Book3S HV: Remove support for dependent threads mode on P9 Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 32/37] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 33/37] KVM: PPC: Book3S HV: small pseries_do_hcall cleanup Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-03-03 20:09   ` Fabiano Rosas
2021-03-03 20:09     ` Fabiano Rosas
2021-03-04 11:05     ` Nicholas Piggin
2021-03-04 11:05       ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 35/37] KVM: PPC: Book3S HV P9: implement hash guest support Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 36/37] KVM: PPC: Book3S HV P9: implement hash host / " Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 37/37] KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths Nicholas Piggin
2021-02-25 13:46   ` Nicholas Piggin

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