From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Ben Gardon <bgardon@google.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Cannon Matthews <cannonmatthews@google.com>,
Paolo Bonzini <pbonzini@redhat.com>, Peter Xu <peterx@redhat.com>,
Peter Shier <pshier@google.com>,
Peter Feiner <pfeiner@google.com>,
Junaid Shahid <junaids@google.com>,
Jim Mattson <jmattson@google.com>,
Yulei Zhang <yulei.kernel@gmail.com>,
Wanpeng Li <kernellwp@gmail.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Xiao Guangrong <xiaoguangrong.eric@gmail.com>
Subject: Re: [PATCH 09/22] kvm: mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
Date: Wed, 30 Sep 2020 09:19:30 -0700 [thread overview]
Message-ID: <20200930161929.GC32672@linux.intel.com> (raw)
In-Reply-To: <20200925212302.3979661-10-bgardon@google.com>
On Fri, Sep 25, 2020 at 02:22:49PM -0700, Ben Gardon wrote:
> In order to avoid creating executable hugepages in the TDP MMU PF
> handler, remove the dependency between disallowed_hugepage_adjust and
> the shadow_walk_iterator. This will open the function up to being used
> by the TDP MMU PF handler in a future patch.
>
> Tested by running kvm-unit-tests and KVM selftests on an Intel Haswell
> machine. This series introduced no new failures.
>
> This series can be viewed in Gerrit at:
> https://linux-review.googlesource.com/c/virt/kvm/kvm/+/2538
>
> Signed-off-by: Ben Gardon <bgardon@google.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 17 +++++++++--------
> arch/x86/kvm/mmu/paging_tmpl.h | 3 ++-
> 2 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 6344e7863a0f5..f6e6fc9959c04 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -3295,13 +3295,12 @@ static int kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, gfn_t gfn,
> return level;
> }
>
> -static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it,
> - gfn_t gfn, kvm_pfn_t *pfnp, int *levelp)
> +static void disallowed_hugepage_adjust(u64 spte, gfn_t gfn, int cur_level,
> + kvm_pfn_t *pfnp, int *goal_levelp)
> {
> - int level = *levelp;
> - u64 spte = *it.sptep;
> + int goal_level = *goal_levelp;
More bikeshedding... Can we keep 'level' and 'levelp' instead of prepending
'goal_'? I get the intent, but goal_level isn't necessarily accurate as the
original requested level (referred to as req_level in the caller in kvm/queue)
may be different than goal_level, i.e. this helper may have already decremented
the level. IMO it's more accurate/correct to keep the plain 'level'.
> - if (it.level == level && level > PG_LEVEL_4K &&
> + if (cur_level == goal_level && goal_level > PG_LEVEL_4K &&
> is_nx_huge_page_enabled() &&
> is_shadow_present_pte(spte) &&
> !is_large_pte(spte)) {
> @@ -3312,9 +3311,10 @@ static void disallowed_hugepage_adjust(struct kvm_shadow_walk_iterator it,
> * patching back for them into pfn the next 9 bits of
> * the address.
> */
> - u64 page_mask = KVM_PAGES_PER_HPAGE(level) - KVM_PAGES_PER_HPAGE(level - 1);
> + u64 page_mask = KVM_PAGES_PER_HPAGE(goal_level) -
> + KVM_PAGES_PER_HPAGE(goal_level - 1);
> *pfnp |= gfn & page_mask;
> - (*levelp)--;
> + (*goal_levelp)--;
> }
> }
>
> @@ -3339,7 +3339,8 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
> * We cannot overwrite existing page tables with an NX
> * large page, as the leaf could be executable.
> */
> - disallowed_hugepage_adjust(it, gfn, &pfn, &level);
> + disallowed_hugepage_adjust(*it.sptep, gfn, it.level,
> + &pfn, &level);
>
> base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
> if (it.level == level)
> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
> index 4dd6b1e5b8cf7..6a8666cb0d24b 100644
> --- a/arch/x86/kvm/mmu/paging_tmpl.h
> +++ b/arch/x86/kvm/mmu/paging_tmpl.h
> @@ -690,7 +690,8 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gpa_t addr,
> * We cannot overwrite existing page tables with an NX
> * large page, as the leaf could be executable.
> */
> - disallowed_hugepage_adjust(it, gw->gfn, &pfn, &hlevel);
> + disallowed_hugepage_adjust(*it.sptep, gw->gfn, it.level,
> + &pfn, &hlevel);
>
> base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
> if (it.level == hlevel)
> --
> 2.28.0.709.gb0816b6eb0-goog
>
next prev parent reply other threads:[~2020-09-30 16:19 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 21:22 [PATCH 00/22] Introduce the TDP MMU Ben Gardon
2020-09-25 21:22 ` [PATCH 01/22] kvm: mmu: Separate making SPTEs from set_spte Ben Gardon
2020-09-30 4:55 ` Sean Christopherson
2020-09-30 23:03 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 02/22] kvm: mmu: Introduce tdp_iter Ben Gardon
2020-09-26 0:04 ` Paolo Bonzini
2020-09-30 5:06 ` Sean Christopherson
2020-09-26 0:54 ` Paolo Bonzini
2020-09-30 5:08 ` Sean Christopherson
2020-09-30 5:24 ` Sean Christopherson
2020-09-30 6:24 ` Paolo Bonzini
2020-09-30 23:20 ` Eric van Tassell
2020-09-30 23:34 ` Paolo Bonzini
2020-10-01 0:07 ` Sean Christopherson
2020-09-25 21:22 ` [PATCH 03/22] kvm: mmu: Init / Uninit the TDP MMU Ben Gardon
2020-09-26 0:06 ` Paolo Bonzini
2020-09-30 5:34 ` Sean Christopherson
2020-09-30 18:36 ` Ben Gardon
2020-09-30 16:57 ` Sean Christopherson
2020-09-30 17:39 ` Paolo Bonzini
2020-09-30 18:42 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 04/22] kvm: mmu: Allocate and free TDP MMU roots Ben Gardon
2020-09-30 6:06 ` Sean Christopherson
2020-09-30 6:26 ` Paolo Bonzini
2020-09-30 15:38 ` Sean Christopherson
2020-10-12 22:59 ` Ben Gardon
2020-10-12 23:59 ` Sean Christopherson
2020-09-25 21:22 ` [PATCH 05/22] kvm: mmu: Add functions to handle changed TDP SPTEs Ben Gardon
2020-09-26 0:39 ` Paolo Bonzini
2020-09-28 17:23 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 06/22] kvm: mmu: Make address space ID a property of memslots Ben Gardon
2020-09-30 6:10 ` Sean Christopherson
2020-09-30 23:11 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 07/22] kvm: mmu: Support zapping SPTEs in the TDP MMU Ben Gardon
2020-09-26 0:14 ` Paolo Bonzini
2020-09-30 6:15 ` Sean Christopherson
2020-09-30 6:28 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 08/22] kvm: mmu: Separate making non-leaf sptes from link_shadow_page Ben Gardon
2020-09-25 21:22 ` [PATCH 09/22] kvm: mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg Ben Gardon
2020-09-30 16:19 ` Sean Christopherson [this message]
2020-09-25 21:22 ` [PATCH 10/22] kvm: mmu: Add TDP MMU PF handler Ben Gardon
2020-09-26 0:24 ` Paolo Bonzini
2020-09-30 16:37 ` Sean Christopherson
2020-09-30 16:55 ` Paolo Bonzini
2020-09-30 17:37 ` Paolo Bonzini
2020-10-06 22:35 ` Ben Gardon
2020-10-06 22:33 ` Ben Gardon
2020-10-07 20:55 ` Sean Christopherson
2020-09-25 21:22 ` [PATCH 11/22] kvm: mmu: Factor out allocating a new tdp_mmu_page Ben Gardon
2020-09-26 0:22 ` Paolo Bonzini
2020-09-30 18:53 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 12/22] kvm: mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU Ben Gardon
2020-09-25 21:22 ` [PATCH 13/22] kvm: mmu: Support invalidate range MMU notifier for " Ben Gardon
2020-09-30 17:03 ` Sean Christopherson
2020-09-30 23:15 ` Ben Gardon
2020-09-30 23:24 ` Sean Christopherson
2020-09-30 23:27 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 14/22] kvm: mmu: Add access tracking for tdp_mmu Ben Gardon
2020-09-26 0:32 ` Paolo Bonzini
2020-09-30 17:48 ` Sean Christopherson
2020-10-06 23:38 ` Ben Gardon
2020-09-25 21:22 ` [PATCH 15/22] kvm: mmu: Support changed pte notifier in tdp MMU Ben Gardon
2020-09-26 0:33 ` Paolo Bonzini
2020-09-28 15:11 ` Paolo Bonzini
2020-10-07 16:53 ` Ben Gardon
2020-10-07 17:18 ` Paolo Bonzini
2020-10-07 17:30 ` Ben Gardon
2020-10-07 17:54 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 16/22] kvm: mmu: Add dirty logging handler for changed sptes Ben Gardon
2020-09-26 0:45 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 17/22] kvm: mmu: Support dirty logging for the TDP MMU Ben Gardon
2020-09-26 1:04 ` Paolo Bonzini
2020-10-08 18:27 ` Ben Gardon
2020-09-29 15:07 ` Paolo Bonzini
2020-09-30 18:04 ` Sean Christopherson
2020-09-30 18:08 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 18/22] kvm: mmu: Support disabling dirty logging for the tdp MMU Ben Gardon
2020-09-26 1:09 ` Paolo Bonzini
2020-10-07 16:30 ` Ben Gardon
2020-10-07 17:21 ` Paolo Bonzini
2020-10-07 17:28 ` Ben Gardon
2020-10-07 17:53 ` Paolo Bonzini
2020-09-25 21:22 ` [PATCH 19/22] kvm: mmu: Support write protection for nesting in " Ben Gardon
2020-09-30 18:06 ` Sean Christopherson
2020-09-25 21:23 ` [PATCH 20/22] kvm: mmu: NX largepage recovery for TDP MMU Ben Gardon
2020-09-26 1:14 ` Paolo Bonzini
2020-09-30 22:23 ` Ben Gardon
2020-09-29 18:24 ` Paolo Bonzini
2020-09-30 18:15 ` Sean Christopherson
2020-09-30 19:56 ` Paolo Bonzini
2020-09-30 22:33 ` Ben Gardon
2020-09-30 22:27 ` Ben Gardon
2020-09-25 21:23 ` [PATCH 21/22] kvm: mmu: Support MMIO in the " Ben Gardon
2020-09-30 18:19 ` Sean Christopherson
2020-09-25 21:23 ` [PATCH 22/22] kvm: mmu: Don't clear write flooding count for direct roots Ben Gardon
2020-09-26 1:25 ` Paolo Bonzini
2020-10-05 22:48 ` Ben Gardon
2020-10-05 23:44 ` Sean Christopherson
2020-10-06 16:19 ` Ben Gardon
2020-09-26 1:14 ` [PATCH 00/22] Introduce the TDP MMU Paolo Bonzini
2020-09-28 17:31 ` Paolo Bonzini
2020-09-29 17:40 ` Ben Gardon
2020-09-29 18:10 ` Paolo Bonzini
2020-09-30 6:19 ` Sean Christopherson
2020-09-30 6:30 ` Paolo Bonzini
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