From: Marc Zyngier <maz@kernel.org>
To: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
kvm@vger.kernel.org, Suzuki K Poulose <suzuki.poulose@arm.com>,
Jintack Lim <jintack@cs.columbia.edu>,
Andre Przywara <andre.przywara@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
kvmarm@lists.cs.columbia.edu, Will Deacon <will@kernel.org>,
George Cherian <gcherian@marvell.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
"Zengtao \(B\)" <prime.zeng@hisilicon.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Dave Martin <Dave.Martin@arm.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 10/26] KVM: arm64: Refactor vcpu_{read,write}_sys_reg
Date: Wed, 27 May 2020 11:04:08 +0100 [thread overview]
Message-ID: <1612302e289ba15fb0ffbfba5ea18e3b@kernel.org> (raw)
In-Reply-To: <09da829c-1640-40fe-313f-df021759fb34@arm.com>
On 2020-05-26 17:28, James Morse wrote:
> Hi Marc,
>
> On 22/04/2020 13:00, Marc Zyngier wrote:
>> Extract the direct HW accessors for later reuse.
>
>> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
>> index 51db934702b64..46f218982df8c 100644
>> --- a/arch/arm64/kvm/sys_regs.c
>> +++ b/arch/arm64/kvm/sys_regs.c
>
>> +u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
>> +{
>> + u64 val = 0x8badf00d8badf00d;
>> +
>> + if (!vcpu->arch.sysregs_loaded_on_cpu) {
>> + goto memory_read;
>> }
>>
>> -immediate_write:
>> + if (__vcpu_read_sys_reg_from_cpu(reg, &val))
>> + return val;
>> +
>> +memory_read:
>> + return __vcpu_sys_reg(vcpu, reg);
>> +}
>
>
> The goto here is a bit odd, is it just an artefact of how we got here?
That's because a lot of this changes when NV gets added to the mix,
see [1].
> Is this easier on the eye?:
> | u64 vcpu_read_sys_reg(const struct kvm_vcpu *vcpu, int reg)
> | {
> | u64 val = 0x8badf00d8badf00d;
> |
> | if (vcpu->arch.sysregs_loaded_on_cpu &&
> | __vcpu_read_sys_reg_from_cpu(reg, &val))
> | return val;
> |
> | return __vcpu_sys_reg(vcpu, reg);
> | }
Definitely. I don't mind reworking the NV branch so that the label
gets introduced there.
>> +void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
>> +{
>> + if (!vcpu->arch.sysregs_loaded_on_cpu)
>> + goto memory_write;
>> +
>> + if (__vcpu_write_sys_reg_to_cpu(val, reg))
>> + return;
>> +
>> +memory_write:
>> __vcpu_sys_reg(vcpu, reg) = val;
>> }
>
> Again I think its clearer without the goto....
>
>
> Regardless:
> Reviewed-by: James Morse <james.morse@arm.com>
Thanks,
M.
[1]
https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/commit/?h=kvm-arm64/nv-5.7-rc1-WIP&id=11f3217d39a602cbfac7d08064c8b31afb57348e
--
Jazz is not dead. It just smells funny...
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next prev parent reply other threads:[~2020-05-27 10:04 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-22 12:00 [PATCH 00/26] KVM: arm64: Preliminary NV patches Marc Zyngier
2020-04-22 12:00 ` [PATCH 01/26] KVM: arm64: Check advertised Stage-2 page size capability Marc Zyngier
2020-04-22 13:40 ` Suzuki K Poulose
2020-04-22 14:07 ` Marc Zyngier
2020-04-22 14:14 ` Suzuki K Poulose
2020-05-07 11:42 ` Alexandru Elisei
2020-04-22 12:00 ` [PATCH 02/26] KVM: arm64: Move __load_guest_stage2 to kvm_mmu.h Marc Zyngier
2020-04-22 13:51 ` Suzuki K Poulose
2020-04-22 13:59 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 03/26] KVM: arm64: Factor out stage 2 page table data from struct kvm Marc Zyngier
2020-05-05 15:26 ` Andrew Scull
2020-05-05 16:32 ` Marc Zyngier
2020-05-05 17:23 ` Andrew Scull
2020-05-05 18:10 ` Marc Zyngier
2020-05-05 16:03 ` James Morse
2020-05-05 17:59 ` Marc Zyngier
2020-05-06 9:30 ` Marc Zyngier
2020-05-11 16:38 ` Alexandru Elisei
2020-05-12 11:17 ` James Morse
2020-05-12 15:47 ` Alexandru Elisei
2020-05-12 16:13 ` James Morse
2020-05-12 16:53 ` Alexandru Elisei
2020-05-27 8:41 ` Marc Zyngier
2020-05-27 8:45 ` Alexandru Elisei
2020-04-22 12:00 ` [PATCH 04/26] arm64: Detect the ARMv8.4 TTL feature Marc Zyngier
2020-04-27 15:55 ` Suzuki K Poulose
2020-04-22 12:00 ` [PATCH 05/26] arm64: Document SW reserved PTE/PMD bits in Stage-2 descriptors Marc Zyngier
2020-05-05 15:59 ` Andrew Scull
2020-05-06 9:39 ` Marc Zyngier
2020-05-06 10:11 ` Andrew Scull
2020-04-22 12:00 ` [PATCH 06/26] arm64: Add level-hinted TLB invalidation helper Marc Zyngier
2020-05-05 17:16 ` Andrew Scull
2020-05-06 8:05 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 07/26] KVM: arm64: Add a level hint to __kvm_tlb_flush_vmid_ipa Marc Zyngier
2020-05-07 15:08 ` Andrew Scull
2020-05-07 15:13 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 08/26] KVM: arm64: Use TTL hint in when invalidating stage-2 translations Marc Zyngier
2020-05-07 15:13 ` Andrew Scull
2020-05-12 12:04 ` James Morse
2020-05-13 9:06 ` Andrew Scull
2020-05-27 8:59 ` Marc Zyngier
2020-05-12 17:26 ` James Morse
2020-04-22 12:00 ` [PATCH 09/26] KVM: arm64: vgic-v3: Take cpu_if pointer directly instead of vcpu Marc Zyngier
2020-05-07 16:26 ` James Morse
2020-05-08 12:20 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 10/26] KVM: arm64: Refactor vcpu_{read,write}_sys_reg Marc Zyngier
2020-05-26 16:28 ` James Morse
2020-05-27 10:04 ` Marc Zyngier [this message]
2020-04-22 12:00 ` [PATCH 11/26] KVM: arm64: Add missing reset handlers for PMU emulation Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-04-22 12:00 ` [PATCH 12/26] KVM: arm64: Move sysreg reset check to boot time Marc Zyngier
2020-04-22 12:00 ` [PATCH 13/26] KVM: arm64: Introduce accessor for ctxt->sys_reg Marc Zyngier
2020-04-22 12:00 ` [PATCH 14/26] KVM: arm64: hyp: Use ctxt_sys_reg/__vcpu_sys_reg instead of raw sys_regs access Marc Zyngier
2020-04-22 12:00 ` [PATCH 15/26] KVM: arm64: sve: Use __vcpu_sys_reg() " Marc Zyngier
2020-04-22 12:00 ` [PATCH 16/26] KVM: arm64: pauth: Use ctxt_sys_reg() " Marc Zyngier
2020-04-22 12:00 ` [PATCH 17/26] KVM: arm64: debug: " Marc Zyngier
2020-04-22 12:00 ` [PATCH 18/26] KVM: arm64: Don't use empty structures as CPU reset state Marc Zyngier
2020-04-24 4:07 ` Zenghui Yu
2020-04-24 7:45 ` Marc Zyngier
2020-04-28 1:34 ` Zengtao (B)
2020-04-22 12:00 ` [PATCH 19/26] KVM: arm64: Make struct kvm_regs userspace-only Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-05-27 10:22 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 20/26] KVM: arm64: Move ELR_EL1 to the system register array Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-05-27 10:36 ` Marc Zyngier
2020-04-22 12:00 ` [PATCH 21/26] KVM: arm64: Move SP_EL1 " Marc Zyngier
2020-05-26 16:29 ` James Morse
2020-04-22 12:00 ` [PATCH 22/26] KVM: arm64: Disintegrate SPSR array Marc Zyngier
2020-05-26 16:30 ` James Morse
2020-04-22 12:00 ` [PATCH 23/26] KVM: arm64: Move SPSR_EL1 to the system register array Marc Zyngier
2020-05-26 16:30 ` James Morse
2020-04-22 12:00 ` [PATCH 24/26] KVM: arm64: timers: Rename kvm_timer_sync_hwstate to kvm_timer_sync_user Marc Zyngier
2020-04-22 12:00 ` [PATCH 25/26] KVM: arm64: timers: Move timer registers to the sys_regs file Marc Zyngier
2020-04-22 12:00 ` [PATCH 26/26] KVM: arm64: Parametrize exception entry with a target EL Marc Zyngier
2020-05-19 10:44 ` Mark Rutland
2020-05-27 9:34 ` Marc Zyngier
2020-05-27 14:41 ` Mark Rutland
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