From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Alexandru Elisei <alexandru.elisei@arm.com>,
Andre Przywara <andre.przywara@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
Russell King <rmk+kernel@armlinux.org.uk>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: Re: [PATCH 12/18] KVM: arm64: nv: Handle PSCI call via smc from the guest
Date: Sat, 11 Feb 2023 18:17:09 +0000 [thread overview]
Message-ID: <Y+fbpcGa9FOntVmJ@linux.dev> (raw)
In-Reply-To: <87pmaglcgw.wl-maz@kernel.org>
On Sat, Feb 11, 2023 at 10:31:59AM +0000, Marc Zyngier wrote:
> On Sat, 11 Feb 2023 10:07:41 +0000, Oliver Upton <oliver.upton@linux.dev> wrote:
[...]
> > This also has the subtle effect of allowing smc instructions from a
> > non-nested guest to hit our hypercall surface too.
>
> I think we'll have to eventually allow that (see the TRNG spec which
> we blatantly deviate from by requiring an HVC), but we don't have to
> cross that bridge just yet.
Perhaps I'll continue to bury my head in the sand and act like you
didn't say that :)
I seem to recall that the SMCCC suggests either the SMC or HVC
instruction could be used if both EL2 and EL3 are implemented. So we've
messed that up too.
My only worry is if we open up the use of SMCs and userspace does
something silly in ACPI/DT and unconditionally picks SMCs over HVCs. The
VM won't get far on pre-NV hardware w/o EL3...
We could always just hide the presence of EL3 for non-NV guests :)
--
Thanks,
Oliver
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next prev parent reply other threads:[~2023-02-11 18:18 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-09 17:58 [PATCH 00/18] KVM: arm64: Prefix patches for NV support Marc Zyngier
2023-02-09 17:58 ` [PATCH 01/18] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier
2023-02-09 17:58 ` [PATCH 02/18] KVM: arm64: Use the S2 MMU context to iterate over S2 table Marc Zyngier
2023-02-11 1:00 ` Andre Przywara
2023-02-09 17:58 ` [PATCH 03/18] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier
2023-02-09 17:58 ` [PATCH 04/18] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier
2023-02-09 17:58 ` [PATCH 05/18] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier
2023-02-09 17:58 ` [PATCH 06/18] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier
2023-02-09 17:58 ` [PATCH 07/18] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier
2023-02-09 17:58 ` [PATCH 08/18] KVM: arm64: nv: Handle HCR_EL2.NV system register traps Marc Zyngier
2023-02-24 17:39 ` Joey Gouly
2023-02-24 18:36 ` Oliver Upton
2023-02-24 19:03 ` Marc Zyngier
2023-02-09 17:58 ` [PATCH 09/18] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier
2023-02-09 17:58 ` [PATCH 10/18] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier
2023-02-09 17:58 ` [PATCH 11/18] KVM: arm64: nv: Handle trapped ERET from " Marc Zyngier
2023-02-09 17:58 ` [PATCH 12/18] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier
2023-02-11 10:07 ` Oliver Upton
2023-02-11 10:31 ` Marc Zyngier
2023-02-11 18:17 ` Oliver Upton [this message]
2023-02-09 17:58 ` [PATCH 13/18] KVM: arm64: nv: Add accessors for SPSR_EL1, ELR_EL1 and VBAR_EL1 from virtual EL2 Marc Zyngier
2023-02-09 17:58 ` [PATCH 14/18] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier
2023-02-09 17:58 ` [PATCH 15/18] KVM: arm64: nv: Allow a sysreg to be hidden from userspace only Marc Zyngier
2023-02-09 17:58 ` [PATCH 16/18] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier
2023-02-09 17:58 ` [PATCH 17/18] KVM: arm64: nv: Filter out unsupported features from ID regs Marc Zyngier
2023-02-09 17:58 ` [PATCH 18/18] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier
2023-02-13 22:26 ` [PATCH 00/18] KVM: arm64: Prefix patches for NV support Oliver Upton
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