From: Julien Grall <Julien.Grall@arm.com>
To: Christoffer Dall <Christoffer.Dall@arm.com>,
"kvmarm@lists.cs.columbia.edu" <kvmarm@lists.cs.columbia.edu>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>, nd <nd@arm.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH 06/14] KVM: arm/arm64: Factor out VMID into struct kvm_vmid
Date: Thu, 21 Feb 2019 11:02:56 +0000 [thread overview]
Message-ID: <1978ee57-c7bd-e55a-4e77-ad0b4b62d1d1@arm.com> (raw)
In-Reply-To: <20190124140032.8588-7-christoffer.dall@arm.com>
Hi Christoffer,
On 24/01/2019 14:00, Christoffer Dall wrote:
> Note that to avoid mapping the kvm_vmid_bits variable into hyp, we
> simply forego the masking of the vmid value in kvm_get_vttbr and rely on
> update_vmid to always assign a valid vmid value (within the supported
> range).
[...]
> - kvm->arch.vmid = kvm_next_vmid;
> + vmid->vmid = kvm_next_vmid;
> kvm_next_vmid++;
> - kvm_next_vmid &= (1 << kvm_vmid_bits) - 1;
> -
> - /* update vttbr to be used with the new vmid */
> - pgd_phys = virt_to_phys(kvm->arch.pgd);
> - BUG_ON(pgd_phys & ~kvm_vttbr_baddr_mask(kvm));
> - vmid = ((u64)(kvm->arch.vmid) << VTTBR_VMID_SHIFT) & VTTBR_VMID_MASK(kvm_vmid_bits);
> - kvm->arch.vttbr = kvm_phys_to_vttbr(pgd_phys) | vmid | cnp;
> + kvm_next_vmid &= (1 << kvm_get_vmid_bits()) - 1;
The arm64 version of kvm_get_vmid_bits does not look cheap. Indeed it required
to read the sanitized value of SYS_ID_AA64MMFR1_EL1 that is implemented using
the function bsearch.
So wouldn't it be better to keep kvm_vmid_bits variable for use in update_vttbr()?
Cheers,
--
Julien Grall
next prev parent reply other threads:[~2019-02-21 11:02 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-24 14:00 [PATCH 00/14] KVM: arm/arm64: Various rework in preparation of nested virt support Christoffer Dall
2019-01-24 14:00 ` [PATCH 01/14] arm/arm64: KVM: Introduce kvm_call_hyp_ret() Christoffer Dall
2019-01-24 14:00 ` [PATCH 02/14] arm64: KVM: Allow for direct call of HYP functions when using VHE Christoffer Dall
2019-01-24 14:00 ` [PATCH 03/14] arm64: KVM: Drop VHE-specific HYP call stub Christoffer Dall
2019-01-24 14:00 ` [PATCH 04/14] ARM: KVM: Teach some form of type-safety to kvm_call_hyp Christoffer Dall
2019-01-24 14:00 ` [PATCH 05/14] arm/arm64: KVM: Statically configure the host's view of MPIDR Christoffer Dall
2019-01-24 14:00 ` [PATCH 06/14] KVM: arm/arm64: Factor out VMID into struct kvm_vmid Christoffer Dall
2019-01-24 19:01 ` James Morse
2019-01-25 10:09 ` Marc Zyngier
2019-01-25 11:05 ` Julien Thierry
2019-01-31 13:01 ` Marc Zyngier
2019-02-21 11:02 ` Julien Grall [this message]
2019-02-22 9:18 ` Marc Zyngier
2019-02-22 11:42 ` Julien Grall
2019-02-22 12:14 ` Marc Zyngier
2019-01-24 14:00 ` [PATCH 07/14] KVM: arm/arm64: Simplify bg_timer programming Christoffer Dall
2019-01-24 14:00 ` [PATCH 08/14] KVM: arm64: Fix ICH_ELRSR_EL2 sysreg naming Christoffer Dall
2019-01-24 14:00 ` [PATCH 09/14] KVM: arm64: Reuse sys_reg() macro when searching the trap table Christoffer Dall
2019-01-30 8:57 ` André Przywara
2019-01-24 14:00 ` [PATCH 10/14] KVM: arm/arm64: consolidate arch timer trap handlers Christoffer Dall
2019-01-25 12:33 ` Julien Thierry
2019-01-30 17:38 ` Marc Zyngier
2019-01-24 14:00 ` [PATCH 11/14] KVM: arm/arm64: timer: Rework data structures for multiple timers Christoffer Dall
2019-02-18 15:10 ` André Przywara
2019-02-19 12:27 ` Christoffer Dall
2019-01-24 14:00 ` [PATCH 12/14] KVM: arm/arm64: arch_timer: Assign the phys timer on VHE systems Christoffer Dall
2019-02-18 15:10 ` André Przywara
2019-02-19 12:43 ` Christoffer Dall
2019-02-20 17:58 ` Andre Przywara
2019-02-19 11:39 ` Alexandru Elisei
2019-02-19 13:03 ` Christoffer Dall
2019-01-24 14:00 ` [PATCH 13/14] KVM: arm/arm64: Rework the timer code to use a timer_map Christoffer Dall
2019-01-24 14:00 ` [PATCH 14/14] KVM: arm/arm64: Move kvm_is_write_fault to header file Christoffer Dall
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=1978ee57-c7bd-e55a-4e77-ad0b4b62d1d1@arm.com \
--to=julien.grall@arm.com \
--cc=Christoffer.Dall@arm.com \
--cc=Marc.Zyngier@arm.com \
--cc=kvm@vger.kernel.org \
--cc=kvmarm@lists.cs.columbia.edu \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=nd@arm.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox