From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: sean.j.christopherson@intel.com, vkuznets@redhat.com
Subject: [PATCH 2/5] KVM: x86: make FNAME(fetch) and __direct_map more similar
Date: Thu, 4 Jul 2019 11:32:53 +0200 [thread overview]
Message-ID: <20190704093256.12989-3-pbonzini@redhat.com> (raw)
In-Reply-To: <20190704093256.12989-1-pbonzini@redhat.com>
These two functions are basically doing the same thing through
kvm_mmu_get_page, link_shadow_page and mmu_set_spte; yet, for historical
reasons, their code looks very different. This patch tries to take the
best of each and make them very similar, so that it is easy to understand
changes that apply to both of them.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/mmu.c | 53 ++++++++++++++++++--------------------
arch/x86/kvm/paging_tmpl.h | 30 ++++++++++-----------
2 files changed, 39 insertions(+), 44 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6fc5c389f5a1..af9dafa54f85 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3181,40 +3181,39 @@ static void direct_pte_prefetch(struct kvm_vcpu *vcpu, u64 *sptep)
__direct_pte_prefetch(vcpu, sp, sptep);
}
-static int __direct_map(struct kvm_vcpu *vcpu, int write, int map_writable,
- int level, gfn_t gfn, kvm_pfn_t pfn, bool prefault)
+static int __direct_map(struct kvm_vcpu *vcpu, gpa_t gpa, int write,
+ int map_writable, int level, kvm_pfn_t pfn,
+ bool prefault)
{
- struct kvm_shadow_walk_iterator iterator;
+ struct kvm_shadow_walk_iterator it;
struct kvm_mmu_page *sp;
- int emulate = 0;
- gfn_t pseudo_gfn;
+ int ret;
+ gfn_t gfn = gpa >> PAGE_SHIFT;
+ gfn_t base_gfn = gfn;
if (!VALID_PAGE(vcpu->arch.mmu->root_hpa))
- return 0;
+ return RET_PF_RETRY;
- for_each_shadow_entry(vcpu, (u64)gfn << PAGE_SHIFT, iterator) {
- if (iterator.level == level) {
- emulate = mmu_set_spte(vcpu, iterator.sptep, ACC_ALL,
- write, level, gfn, pfn, prefault,
- map_writable);
- direct_pte_prefetch(vcpu, iterator.sptep);
- ++vcpu->stat.pf_fixed;
+ for_each_shadow_entry(vcpu, gpa, it) {
+ base_gfn = gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+ if (it.level == level)
break;
- }
- drop_large_spte(vcpu, iterator.sptep);
- if (!is_shadow_present_pte(*iterator.sptep)) {
- u64 base_addr = iterator.addr;
+ drop_large_spte(vcpu, it.sptep);
+ if (!is_shadow_present_pte(*it.sptep)) {
+ sp = kvm_mmu_get_page(vcpu, base_gfn, it.addr,
+ it.level - 1, true, ACC_ALL);
- base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
- pseudo_gfn = base_addr >> PAGE_SHIFT;
- sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
- iterator.level - 1, 1, ACC_ALL);
-
- link_shadow_page(vcpu, iterator.sptep, sp);
+ link_shadow_page(vcpu, it.sptep, sp);
}
}
- return emulate;
+
+ ret = mmu_set_spte(vcpu, it.sptep, ACC_ALL,
+ write, level, base_gfn, pfn, prefault,
+ map_writable);
+ direct_pte_prefetch(vcpu, it.sptep);
+ ++vcpu->stat.pf_fixed;
+ return ret;
}
static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct *tsk)
@@ -3538,8 +3537,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, u32 error_code,
goto out_unlock;
if (likely(!force_pt_level))
transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
- r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-
+ r = __direct_map(vcpu, v, write, map_writable, level, pfn, prefault);
out_unlock:
spin_unlock(&vcpu->kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
@@ -4165,8 +4163,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, u32 error_code,
goto out_unlock;
if (likely(!force_pt_level))
transparent_hugepage_adjust(vcpu, &gfn, &pfn, &level);
- r = __direct_map(vcpu, write, map_writable, level, gfn, pfn, prefault);
-
+ r = __direct_map(vcpu, gpa, write, map_writable, level, pfn, prefault);
out_unlock:
spin_unlock(&vcpu->kvm->mmu_lock);
kvm_release_pfn_clean(pfn);
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 2db96401178e..bfd89966832b 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -623,6 +623,7 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
struct kvm_shadow_walk_iterator it;
unsigned direct_access, access = gw->pt_access;
int top_level, ret;
+ gfn_t base_gfn;
direct_access = gw->pte_access;
@@ -667,31 +668,29 @@ static int FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
link_shadow_page(vcpu, it.sptep, sp);
}
- for (;
- shadow_walk_okay(&it) && it.level > hlevel;
- shadow_walk_next(&it)) {
- gfn_t direct_gfn;
+ base_gfn = gw->gfn;
+ for (; shadow_walk_okay(&it); shadow_walk_next(&it)) {
clear_sp_write_flooding_count(it.sptep);
+ base_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
+ if (it.level == hlevel)
+ break;
+
validate_direct_spte(vcpu, it.sptep, direct_access);
drop_large_spte(vcpu, it.sptep);
- if (is_shadow_present_pte(*it.sptep))
- continue;
-
- direct_gfn = gw->gfn & ~(KVM_PAGES_PER_HPAGE(it.level) - 1);
-
- sp = kvm_mmu_get_page(vcpu, direct_gfn, addr, it.level-1,
- true, direct_access);
- link_shadow_page(vcpu, it.sptep, sp);
+ if (!is_shadow_present_pte(*it.sptep)) {
+ sp = kvm_mmu_get_page(vcpu, base_gfn, addr,
+ it.level - 1, true, direct_access);
+ link_shadow_page(vcpu, it.sptep, sp);
+ }
}
- clear_sp_write_flooding_count(it.sptep);
ret = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault,
- it.level, gw->gfn, pfn, prefault, map_writable);
+ it.level, base_gfn, pfn, prefault, map_writable);
FNAME(pte_prefetch)(vcpu, gw, it.sptep);
-
+ ++vcpu->stat.pf_fixed;
return ret;
out_gpte_changed:
@@ -854,7 +853,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code,
transparent_hugepage_adjust(vcpu, &walker.gfn, &pfn, &level);
r = FNAME(fetch)(vcpu, addr, &walker, write_fault,
level, pfn, map_writable, prefault);
- ++vcpu->stat.pf_fixed;
kvm_mmu_audit(vcpu, AUDIT_POST_PAGE_FAULT);
out_unlock:
--
2.21.0
next prev parent reply other threads:[~2019-07-04 9:33 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-04 9:32 [PATCH 0/5] KVM: some x86 MMU cleanup and new tracepoints Paolo Bonzini
2019-07-04 9:32 ` [PATCH 1/5] kvm: x86: Do not release the page inside mmu_set_spte() Paolo Bonzini
2019-07-04 9:32 ` Paolo Bonzini [this message]
2019-07-04 9:32 ` [PATCH 3/5] KVM: x86: remove now unneeded hugepage gfn adjustment Paolo Bonzini
2019-07-04 9:32 ` [PATCH 4/5] KVM: x86: change kvm_mmu_page_get_gfn BUG_ON to WARN_ON Paolo Bonzini
2019-07-04 9:32 ` [PATCH 5/5] KVM: x86: add tracepoints around __direct_map and FNAME(fetch) Paolo Bonzini
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=20190704093256.12989-3-pbonzini@redhat.com \
--to=pbonzini@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=sean.j.christopherson@intel.com \
--cc=vkuznets@redhat.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;
as well as URLs for NNTP newsgroup(s).