Re: [PATCH v8 00/14] KVM TDX: TDP MMU: large page support

From: "Yin, Fengwei" <fengwei.yin@intel.com>
To: <isaku.yamahata@intel.com>, <kvm@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Cc: <isaku.yamahata@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>,
	<erdemaktas@google.com>, Sean Christopherson <seanjc@google.com>,
	Sagi Shahar <sagis@google.com>, Kai Huang <kai.huang@intel.com>,
	<chen.bo@intel.com>, <hang.yuan@intel.com>,
	<tina.zhang@intel.com>, "Li, Xiaoyao" <xiaoyao.li@intel.com>
Subject: Re: [PATCH v8 00/14] KVM TDX: TDP MMU: large page support
Date: Wed, 27 Mar 2024 08:53:50 +0800	[thread overview]
Message-ID: <8f7735aa-517f-4bb3-8e33-d58a27c2a822@intel.com> (raw)
In-Reply-To: <cover.1708933624.git.isaku.yamahata@intel.com>

Hi Isaku,

On 2/26/2024 4:29 PM, isaku.yamahata@intel.com wrote:
> From: Isaku Yamahata <isaku.yamahata@intel.com>
> 
> This patch series is based on "v19 KVM TDX: basic feature support".  It
> implements large page support for TDP MMU by allowing populating of the large
> page and splitting it when necessary.
To test the hugepage for TDX guest, we need to apply Qemu patch
from Xiaoyao:
https://lore.kernel.org/qemu-devel/20231115071519.2864957-4-xiaoyao.li@intel.com/

According to Xiaoyao, it's still under discussion. So he didn't
send updated version patch. For folks want to try this series,
it may be better to mention above link in this cover letter?

Test in my side showed several benchmarks got 10+% performance
gain which is really nice. So:
Tested-by: Yin Fengwei <fengwei.yin@intel.com>

Regards
Yin, Fengwei

> 
> No major changes from v7 instead of rebasing.
> 
> Thanks,
> 
> Changes from v7:
> - Rebased to v19 TDX KVM v6.8-rc5 based patch series
> 
> Changes from v6:
> - Rebased to v18 TDX KVM v6.8-rc1 based patch series
> - use struct tdx_module_args
> - minor improve on comment, commit message
> 
> Changes from v5:
> - Switched to TDX module 1.5 base.
> 
> Chnages from v4:
> - Rebased to v16 TDX KVM v6.6-rc2 base
> 
> Changes from v3:
> - Rebased to v15 TDX KVM v6.5-rc1 base
> 
> Changes from v2:
> - implemented page merging path
> - rebased to TDX KVM v11
> 
> Changes from v1:
> - implemented page merging path
> - rebased to UPM v10
> - rebased to TDX KVM v10
> - rebased to kvm.git queue + v6.1-rc8
> 
> Isaku Yamahata (4):
>    KVM: x86/tdp_mmu: Allocate private page table for large page split
>    KVM: x86/tdp_mmu: Try to merge pages into a large page
>    KVM: TDX: Implement merge pages into a large page
>    KVM: x86/mmu: Make kvm fault handler aware of large page of private
>      memslot
> 
> Sean Christopherson (1):
>    KVM: Add transparent hugepage support for dedicated guest memory
> 
> Xiaoyao Li (9):
>    KVM: TDX: Flush cache based on page size before TDX SEAMCALL
>    KVM: TDX: Pass KVM page level to tdh_mem_page_aug()
>    KVM: TDX: Pass size to reclaim_page()
>    KVM: TDX: Update tdx_sept_{set,drop}_private_spte() to support large
>      page
>    KVM: MMU: Introduce level info in PFERR code
>    KVM: TDX: Pass desired page level in err code for page fault handler
>    KVM: x86/tdp_mmu: Split the large page when zap leaf
>    KVM: x86/tdp_mmu, TDX: Split a large page when 4KB page within it
>      converted to shared
>    KVM: TDX: Allow 2MB large page for TD GUEST
> 
>   Documentation/virt/kvm/api.rst     |   7 +
>   arch/x86/include/asm/kvm-x86-ops.h |   3 +
>   arch/x86/include/asm/kvm_host.h    |  11 ++
>   arch/x86/kvm/mmu/mmu.c             |  38 ++--
>   arch/x86/kvm/mmu/mmu_internal.h    |  30 +++-
>   arch/x86/kvm/mmu/tdp_iter.c        |  37 +++-
>   arch/x86/kvm/mmu/tdp_iter.h        |   2 +
>   arch/x86/kvm/mmu/tdp_mmu.c         | 276 ++++++++++++++++++++++++++---
>   arch/x86/kvm/vmx/common.h          |   6 +-
>   arch/x86/kvm/vmx/tdx.c             | 221 +++++++++++++++++------
>   arch/x86/kvm/vmx/tdx_arch.h        |  21 +++
>   arch/x86/kvm/vmx/tdx_errno.h       |   3 +
>   arch/x86/kvm/vmx/tdx_ops.h         |  56 ++++--
>   arch/x86/kvm/vmx/vmx.c             |   2 +-
>   include/uapi/linux/kvm.h           |   2 +
>   virt/kvm/guest_memfd.c             |  73 +++++++-
>   16 files changed, 672 insertions(+), 116 deletions(-)
> 