All of lore.kernel.org
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>,
	kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: Re: [PATCH 07/11] KVM: arm64: Inject AArch64 exceptions from HYP
Date: Tue, 27 Oct 2020 16:21:36 +0000	[thread overview]
Message-ID: <e38ae1cbc11ea00920067b886e1898d5@kernel.org> (raw)
In-Reply-To: <20201026142201.GH12454@C02TD0UTHF1T.local>

On 2020-10-26 14:22, Mark Rutland wrote:
> On Mon, Oct 26, 2020 at 01:34:46PM +0000, Marc Zyngier wrote:
>> Move the AArch64 exception injection code from EL1 to HYP, leaving
>> only the ESR_EL1 updates to EL1. In order to come with the differences
>> between VHE and nVHE, two set of system register accessors are 
>> provided.
>> 
>> SPSR, ELR, PC and PSTATE are now completely handled in the hypervisor.
>> 
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
> 
>>  void kvm_inject_exception(struct kvm_vcpu *vcpu)
>>  {
>> +	switch (vcpu->arch.flags & KVM_ARM64_EXCEPT_MASK) {
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SYNC:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_IRQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_irq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_FIQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_fiq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SERR:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_serror);
>> +		break;
>> +	default:
>> +		/* EL2 are unimplemented until we get NV. One day. */
>> +		break;
>> +	}
>>  }
> 
> Huh, we're going to allow EL1 to inject IRQ/FIQ/SERROR *exceptions*
> directly, rather than pending those via HCR_EL2.{VI,VF,VSE}? We never
> used to have code to do that.

True, and I feel like I got carried away while thinking of NV.
Though James had some "interesting" use case [1] lately...

> If we're going to support that we'll need to check against the DAIF 
> bits
> to make sure we don't inject an exception that can't be architecturally
> taken.

Nah, forget it. Unless we really need to implement something like James'
idea, I'd rather drop this altogether.

> I guess we'll tighten that up along with the synchronous exception
> checks, but given those three cases aren't needed today it might be
> worth removing them from the switch for now and/or adding a comment to
> that effect.

Agreed.

         M.

[1] https://lore.kernel.org/r/20201023165108.15061-1-james.morse@arm.com
-- 
Jazz is not dead. It just smells funny...
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>,
	kernel-team@android.com, kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org
Subject: Re: [PATCH 07/11] KVM: arm64: Inject AArch64 exceptions from HYP
Date: Tue, 27 Oct 2020 16:21:36 +0000	[thread overview]
Message-ID: <e38ae1cbc11ea00920067b886e1898d5@kernel.org> (raw)
In-Reply-To: <20201026142201.GH12454@C02TD0UTHF1T.local>

On 2020-10-26 14:22, Mark Rutland wrote:
> On Mon, Oct 26, 2020 at 01:34:46PM +0000, Marc Zyngier wrote:
>> Move the AArch64 exception injection code from EL1 to HYP, leaving
>> only the ESR_EL1 updates to EL1. In order to come with the differences
>> between VHE and nVHE, two set of system register accessors are 
>> provided.
>> 
>> SPSR, ELR, PC and PSTATE are now completely handled in the hypervisor.
>> 
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
> 
>>  void kvm_inject_exception(struct kvm_vcpu *vcpu)
>>  {
>> +	switch (vcpu->arch.flags & KVM_ARM64_EXCEPT_MASK) {
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SYNC:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_IRQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_irq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_FIQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_fiq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SERR:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_serror);
>> +		break;
>> +	default:
>> +		/* EL2 are unimplemented until we get NV. One day. */
>> +		break;
>> +	}
>>  }
> 
> Huh, we're going to allow EL1 to inject IRQ/FIQ/SERROR *exceptions*
> directly, rather than pending those via HCR_EL2.{VI,VF,VSE}? We never
> used to have code to do that.

True, and I feel like I got carried away while thinking of NV.
Though James had some "interesting" use case [1] lately...

> If we're going to support that we'll need to check against the DAIF 
> bits
> to make sure we don't inject an exception that can't be architecturally
> taken.

Nah, forget it. Unless we really need to implement something like James'
idea, I'd rather drop this altogether.

> I guess we'll tighten that up along with the synchronous exception
> checks, but given those three cases aren't needed today it might be
> worth removing them from the switch for now and/or adding a comment to
> that effect.

Agreed.

         M.

[1] https://lore.kernel.org/r/20201023165108.15061-1-james.morse@arm.com
-- 
Jazz is not dead. It just smells funny...

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID (diff)
From: Marc Zyngier <maz@kernel.org>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
	kernel-team@android.com, Will Deacon <will@kernel.org>
Subject: Re: [PATCH 07/11] KVM: arm64: Inject AArch64 exceptions from HYP
Date: Tue, 27 Oct 2020 16:21:36 +0000	[thread overview]
Message-ID: <e38ae1cbc11ea00920067b886e1898d5@kernel.org> (raw)
In-Reply-To: <20201026142201.GH12454@C02TD0UTHF1T.local>

On 2020-10-26 14:22, Mark Rutland wrote:
> On Mon, Oct 26, 2020 at 01:34:46PM +0000, Marc Zyngier wrote:
>> Move the AArch64 exception injection code from EL1 to HYP, leaving
>> only the ESR_EL1 updates to EL1. In order to come with the differences
>> between VHE and nVHE, two set of system register accessors are 
>> provided.
>> 
>> SPSR, ELR, PC and PSTATE are now completely handled in the hypervisor.
>> 
>> Signed-off-by: Marc Zyngier <maz@kernel.org>
> 
>>  void kvm_inject_exception(struct kvm_vcpu *vcpu)
>>  {
>> +	switch (vcpu->arch.flags & KVM_ARM64_EXCEPT_MASK) {
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SYNC:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_IRQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_irq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_FIQ:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_fiq);
>> +		break;
>> +	case KVM_ARM64_EXCEPT_AA64_EL1_SERR:
>> +		enter_exception64(vcpu, PSR_MODE_EL1h, except_type_serror);
>> +		break;
>> +	default:
>> +		/* EL2 are unimplemented until we get NV. One day. */
>> +		break;
>> +	}
>>  }
> 
> Huh, we're going to allow EL1 to inject IRQ/FIQ/SERROR *exceptions*
> directly, rather than pending those via HCR_EL2.{VI,VF,VSE}? We never
> used to have code to do that.

True, and I feel like I got carried away while thinking of NV.
Though James had some "interesting" use case [1] lately...

> If we're going to support that we'll need to check against the DAIF 
> bits
> to make sure we don't inject an exception that can't be architecturally
> taken.

Nah, forget it. Unless we really need to implement something like James'
idea, I'd rather drop this altogether.

> I guess we'll tighten that up along with the synchronous exception
> checks, but given those three cases aren't needed today it might be
> worth removing them from the switch for now and/or adding a comment to
> that effect.

Agreed.

         M.

[1] https://lore.kernel.org/r/20201023165108.15061-1-james.morse@arm.com
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2020-10-27 16:21 UTC|newest]

Thread overview: 102+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-26 13:34 [PATCH 00/11] KVM: arm64: Move PC/ELR/SPSR/PSTATE updatess to EL2 Marc Zyngier
2020-10-26 13:34 ` Marc Zyngier
2020-10-26 13:34 ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 01/11] KVM: arm64: Don't adjust PC on SError during SMC trap Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:53   ` Mark Rutland
2020-10-26 13:53     ` Mark Rutland
2020-10-26 13:53     ` Mark Rutland
2020-10-26 14:08     ` Marc Zyngier
2020-10-26 14:08       ` Marc Zyngier
2020-10-26 14:08       ` Marc Zyngier
2020-10-26 14:22       ` Mark Rutland
2020-10-26 14:22         ` Mark Rutland
2020-10-26 14:22         ` Mark Rutland
2020-10-26 13:34 ` [PATCH 02/11] KVM: arm64: Move kvm_vcpu_trap_il_is32bit into kvm_skip_instr32() Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:55   ` Mark Rutland
2020-10-26 13:55     ` Mark Rutland
2020-10-26 13:55     ` Mark Rutland
2020-10-26 13:34 ` [PATCH 03/11] KVM: arm64: Make kvm_skip_instr() and co private to HYP Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:04   ` Mark Rutland
2020-10-26 14:04     ` Mark Rutland
2020-10-26 14:04     ` Mark Rutland
2020-10-27 16:17     ` Marc Zyngier
2020-10-27 16:17       ` Marc Zyngier
2020-10-27 16:17       ` Marc Zyngier
2020-10-27 10:55   ` Suzuki K Poulose
2020-10-27 10:55     ` Suzuki K Poulose
2020-10-27 10:55     ` Suzuki K Poulose
2020-10-27 11:08     ` Marc Zyngier
2020-10-27 11:08       ` Marc Zyngier
2020-10-27 11:08       ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 04/11] KVM: arm64: Move PC rollback on SError " Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:06   ` Mark Rutland
2020-10-26 14:06     ` Mark Rutland
2020-10-26 14:06     ` Mark Rutland
2020-10-27 14:56   ` James Morse
2020-10-27 14:56     ` James Morse
2020-10-27 14:56     ` James Morse
2020-10-27 14:59     ` Marc Zyngier
2020-10-27 14:59       ` Marc Zyngier
2020-10-27 14:59       ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 05/11] KVM: arm64: Move VHE direct sysreg accessors into kvm_host.h Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:07   ` Mark Rutland
2020-10-26 14:07     ` Mark Rutland
2020-10-26 14:07     ` Mark Rutland
2020-10-26 13:34 ` [PATCH 06/11] KVM: arm64: Add basic hooks for injecting exceptions from EL2 Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 07/11] KVM: arm64: Inject AArch64 exceptions from HYP Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:22   ` Mark Rutland
2020-10-26 14:22     ` Mark Rutland
2020-10-26 14:22     ` Mark Rutland
2020-10-27 16:21     ` Marc Zyngier [this message]
2020-10-27 16:21       ` Marc Zyngier
2020-10-27 16:21       ` Marc Zyngier
2020-10-27 17:41   ` James Morse
2020-10-27 17:41     ` James Morse
2020-10-27 17:41     ` James Morse
2020-10-27 18:49     ` Marc Zyngier
2020-10-27 18:49       ` Marc Zyngier
2020-10-27 18:49       ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 08/11] KVM: arm64: Inject AArch32 " Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:26   ` Mark Rutland
2020-10-26 14:26     ` Mark Rutland
2020-10-26 14:26     ` Mark Rutland
2020-10-27 17:41   ` James Morse
2020-10-27 17:41     ` James Morse
2020-10-27 17:41     ` James Morse
2020-10-27 19:21     ` Marc Zyngier
2020-10-27 19:21       ` Marc Zyngier
2020-10-27 19:21       ` Marc Zyngier
2020-10-28 19:20       ` James Morse
2020-10-28 19:20         ` James Morse
2020-10-28 19:20         ` James Morse
2020-10-28 20:24         ` Marc Zyngier
2020-10-28 20:24           ` Marc Zyngier
2020-10-28 20:24           ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 09/11] KVM: arm64: Remove SPSR manipulation primitives Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 14:30   ` Mark Rutland
2020-10-26 14:30     ` Mark Rutland
2020-10-26 14:30     ` Mark Rutland
2020-10-26 13:34 ` [PATCH 10/11] KVM: arm64: Consolidate exception injection Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34 ` [PATCH 11/11] KVM: arm64: Get rid of the AArch32 register mapping code Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier
2020-10-26 13:34   ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=e38ae1cbc11ea00920067b886e1898d5@kernel.org \
    --to=maz@kernel.org \
    --cc=kernel-team@android.com \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=mark.rutland@arm.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.