From: Daniel Axtens <dja@axtens•net>
To: Nicholas Piggin <npiggin@gmail•com>, kvm-ppc@vger•kernel.org
Cc: linuxppc-dev@lists•ozlabs.org,
Nicholas Piggin <npiggin@gmail•com>,
Fabiano Rosas <farosas@linux•ibm.com>
Subject: Re: [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler
Date: Fri, 26 Feb 2021 16:44:39 +1100 [thread overview]
Message-ID: <8735xj9yd4.fsf@linkitivity.dja.id.au> (raw)
In-Reply-To: <20210225134652.2127648-5-npiggin@gmail.com>
Nicholas Piggin <npiggin@gmail•com> writes:
> The code being executed in KVM_GUEST_MODE_SKIP is hypervisor code with
> MSR[IR]=0, so the faults of concern are the d-side ones caused by access
> to guest context by the hypervisor.
>
> Instruction breakpoint interrupts are not a concern here. It's unlikely
> any good would come of causing breaks in this code, but skipping the
> instruction that caused it won't help matters (e.g., skip the mtmsr that
> sets MSR[DR]=0 or clears KVM_GUEST_MODE_SKIP).
I'm not entirely clear on the example here, but the patch makes sense
and I can follow your logic for removing the IKVM_SKIP handler from the
instruction breakpoint exception.
On that basis:
Reviewed-by: Daniel Axtens <dja@axtens•net>
Kind regards,
Daniel
>
> Reviewed-by: Fabiano Rosas <farosas@linux•ibm.com>
> Signed-off-by: Nicholas Piggin <npiggin@gmail•com>
> ---
> arch/powerpc/kernel/exceptions-64s.S | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index a027600beeb1..0097e0676ed7 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -2553,7 +2553,6 @@ EXC_VIRT_NONE(0x5200, 0x100)
> INT_DEFINE_BEGIN(instruction_breakpoint)
> IVEC=0x1300
> #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> - IKVM_SKIP=1
> IKVM_REAL=1
> #endif
> INT_DEFINE_END(instruction_breakpoint)
> --
> 2.23.0
next prev parent reply other threads:[~2021-02-26 5:45 UTC|newest]
Thread overview: 67+ 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 ` [PATCH v2 01/37] KVM: PPC: Book3S 64: remove unused kvmppc_h_protect argument Nicholas Piggin
2021-02-26 5:01 ` Daniel Axtens
2021-02-26 23:50 ` Nicholas Piggin
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
2021-02-26 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 ` [PATCH v2 04/37] powerpc/64s: remove KVM SKIP test from instruction breakpoint handler Nicholas Piggin
2021-02-26 5:44 ` Daniel Axtens [this message]
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
2021-02-26 6:06 ` Daniel Axtens
2021-02-26 23:55 ` Nicholas Piggin
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
2021-03-05 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
2021-03-05 5:54 ` Daniel Axtens
2021-02-25 13:46 ` [PATCH v2 08/37] KVM: PPC: Book3S 64: add hcall interrupt handler Nicholas Piggin
2021-03-05 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
2021-03-05 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 ` [PATCH v2 11/37] KVM: PPC: Book3S 64: move bad_host_intr check to HV handler 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 ` [PATCH v2 13/37] KVM: PPC: Book3S HV P9: Move radix MMU switching instructions together Nicholas Piggin
2021-02-26 15:56 ` Fabiano Rosas
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 ` [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 ` [PATCH v2 16/37] KVM: PPC: Book3S HV P9: Stop handling hcalls in real-mode in the P9 path Nicholas Piggin
2021-02-25 14:51 ` Cédric Le Goater
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
2021-02-26 16:38 ` Fabiano Rosas
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 ` [PATCH v2 19/37] KVM: PPC: Book3S HV P9: Use host timer accounting to avoid decrementer read 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 ` [PATCH v2 21/37] powerpc: add set_dec_or_work API for safely updating decrementer 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 ` [PATCH v2 23/37] KVM: PPC: Book3S HV P9: Implement the rest of the P9 path in C Nicholas Piggin
2021-02-26 22:37 ` Fabiano Rosas
2021-02-27 0:21 ` 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
2021-03-02 13:48 ` 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 ` [PATCH v2 26/37] KVM: PPC: Book3S HV P9: Improve exit timing accounting coverage 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 ` [PATCH v2 28/37] KVM: PPC: Book3S HV P9: Add helpers for OS SPR handling Nicholas Piggin
2021-03-02 15:04 ` Fabiano Rosas
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 ` [PATCH v2 30/37] KVM: PPC: Book3S HV: Implement radix prefetch workaround by disabling MMU Nicholas Piggin
2021-03-02 21:21 ` Fabiano Rosas
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 ` [PATCH v2 32/37] KVM: PPC: Book3S HV: Remove radix guest support from P7/8 path 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 ` [PATCH v2 34/37] KVM: PPC: Book3S HV: add virtual mode handlers for HPT hcalls and page faults Nicholas Piggin
2021-03-03 20:09 ` Fabiano Rosas
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 ` [PATCH v2 36/37] KVM: PPC: Book3S HV P9: implement hash host / " Nicholas Piggin
2021-02-25 13:46 ` [PATCH v2 37/37] KVM: PPC: Book3S HV: remove POWER9 support from P7/8 paths Nicholas Piggin
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