From: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
To: Paolo Bonzini <pbonzini@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
Igor Mammedov <imammedo@redhat.com>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Huacai Chen <chenhuacai@kernel.org>,
Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
Paul Mackerras <paulus@ozlabs.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Janosch Frank <frankja@linux.ibm.com>,
David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Claudio Imbrenda <imbrenda@linux.ibm.com>,
Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v3 2/8] KVM: Integrate gfn_to_memslot_approx() into search_memslots()
Date: Sun, 16 May 2021 23:44:28 +0200 [thread overview]
Message-ID: <b8258ced64a81c7d90320c2921fe08b11eb47362.1621191551.git.maciej.szmigiero@oracle.com> (raw)
In-Reply-To: <cover.1621191549.git.maciej.szmigiero@oracle.com>
From: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
s390 arch has gfn_to_memslot_approx() which is almost identical to
search_memslots(), differing only in that in case the gfn falls in a hole
one of the memslots bordering the hole is returned.
Add this lookup mode as an option to search_memslots() so we don't have two
almost identical functions for looking up a memslot by its gfn.
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
---
arch/powerpc/kvm/book3s_64_vio.c | 2 +-
arch/powerpc/kvm/book3s_64_vio_hv.c | 2 +-
arch/s390/kvm/kvm-s390.c | 39 ++---------------------------
include/linux/kvm_host.h | 13 +++++++---
4 files changed, 14 insertions(+), 42 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 8da93fdfa59e..148525120504 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -346,7 +346,7 @@ static long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce,
unsigned long gfn = tce >> PAGE_SHIFT;
struct kvm_memory_slot *memslot;
- memslot = search_memslots(kvm_memslots(kvm), gfn);
+ memslot = search_memslots(kvm_memslots(kvm), gfn, false);
if (!memslot)
return -EINVAL;
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c b/arch/powerpc/kvm/book3s_64_vio_hv.c
index 083a4e037718..a4042403630d 100644
--- a/arch/powerpc/kvm/book3s_64_vio_hv.c
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -80,7 +80,7 @@ static long kvmppc_rm_tce_to_ua(struct kvm *kvm,
unsigned long gfn = tce >> PAGE_SHIFT;
struct kvm_memory_slot *memslot;
- memslot = search_memslots(kvm_memslots_raw(kvm), gfn);
+ memslot = search_memslots(kvm_memslots_raw(kvm), gfn, false);
if (!memslot)
return -EINVAL;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1296fc10f80c..75e635ede6ff 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1921,41 +1921,6 @@ static long kvm_s390_set_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
/* for consistency */
#define KVM_S390_CMMA_SIZE_MAX ((u32)KVM_S390_SKEYS_MAX)
-/*
- * Similar to gfn_to_memslot, but returns the index of a memslot also when the
- * address falls in a hole. In that case the index of one of the memslots
- * bordering the hole is returned.
- */
-static int gfn_to_memslot_approx(struct kvm_memslots *slots, gfn_t gfn)
-{
- int start = 0, end = slots->used_slots;
- int slot = atomic_read(&slots->lru_slot);
- struct kvm_memory_slot *memslots = slots->memslots;
-
- if (gfn >= memslots[slot].base_gfn &&
- gfn < memslots[slot].base_gfn + memslots[slot].npages)
- return slot;
-
- while (start < end) {
- slot = start + (end - start) / 2;
-
- if (gfn >= memslots[slot].base_gfn)
- end = slot;
- else
- start = slot + 1;
- }
-
- if (start >= slots->used_slots)
- return slots->used_slots - 1;
-
- if (gfn >= memslots[start].base_gfn &&
- gfn < memslots[start].base_gfn + memslots[start].npages) {
- atomic_set(&slots->lru_slot, start);
- }
-
- return start;
-}
-
static int kvm_s390_peek_cmma(struct kvm *kvm, struct kvm_s390_cmma_log *args,
u8 *res, unsigned long bufsize)
{
@@ -1982,8 +1947,8 @@ static int kvm_s390_peek_cmma(struct kvm *kvm, struct kvm_s390_cmma_log *args,
static unsigned long kvm_s390_next_dirty_cmma(struct kvm_memslots *slots,
unsigned long cur_gfn)
{
- int slotidx = gfn_to_memslot_approx(slots, cur_gfn);
- struct kvm_memory_slot *ms = slots->memslots + slotidx;
+ struct kvm_memory_slot *ms = search_memslots(slots, cur_gfn, true);
+ int slotidx = ms - slots->memslots;
unsigned long ofs = cur_gfn - ms->base_gfn;
if (ms->base_gfn + ms->npages <= cur_gfn) {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8895b95b6a22..3c40c7d32f7e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1091,10 +1091,14 @@ bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args);
* gfn_to_memslot() itself isn't here as an inline because that would
* bloat other code too much.
*
+ * With "approx" set returns the memslot also when the address falls
+ * in a hole. In that case one of the memslots bordering the hole is
+ * returned.
+ *
* IMPORTANT: Slots are sorted from highest GFN to lowest GFN!
*/
static inline struct kvm_memory_slot *
-search_memslots(struct kvm_memslots *slots, gfn_t gfn)
+search_memslots(struct kvm_memslots *slots, gfn_t gfn, bool approx)
{
int start = 0, end = slots->used_slots;
int slot = atomic_read(&slots->lru_slot);
@@ -1116,19 +1120,22 @@ search_memslots(struct kvm_memslots *slots, gfn_t gfn)
start = slot + 1;
}
+ if (approx && start >= slots->used_slots)
+ return &memslots[slots->used_slots - 1];
+
if (start < slots->used_slots && gfn >= memslots[start].base_gfn &&
gfn < memslots[start].base_gfn + memslots[start].npages) {
atomic_set(&slots->lru_slot, start);
return &memslots[start];
}
- return NULL;
+ return approx ? &memslots[start] : NULL;
}
static inline struct kvm_memory_slot *
__gfn_to_memslot(struct kvm_memslots *slots, gfn_t gfn)
{
- return search_memslots(slots, gfn);
+ return search_memslots(slots, gfn, false);
}
static inline unsigned long
next prev parent reply other threads:[~2021-05-16 21:45 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-16 21:44 [PATCH v3 0/8] KVM: Scalable memslots implementation Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 1/8] KVM: x86: Cache total page count to avoid traversing the memslot array Maciej S. Szmigiero
2021-05-19 21:00 ` Sean Christopherson
2021-05-21 7:03 ` Maciej S. Szmigiero
2021-05-16 21:44 ` Maciej S. Szmigiero [this message]
2021-05-19 21:24 ` [PATCH v3 2/8] KVM: Integrate gfn_to_memslot_approx() into search_memslots() Sean Christopherson
2021-05-21 7:03 ` Maciej S. Szmigiero
2021-06-10 16:17 ` Paolo Bonzini
2021-05-16 21:44 ` [PATCH v3 3/8] KVM: Resolve memslot ID via a hash table instead of via a static array Maciej S. Szmigiero
2021-05-19 22:31 ` Sean Christopherson
2021-05-21 7:05 ` Maciej S. Szmigiero
2021-05-22 11:11 ` Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 4/8] KVM: Introduce memslots hva tree Maciej S. Szmigiero
2021-05-19 23:07 ` Sean Christopherson
2021-05-21 7:06 ` Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 5/8] KVM: s390: Introduce kvm_s390_get_gfn_end() Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 6/8] KVM: Keep memslots in tree-based structures instead of array-based ones Maciej S. Szmigiero
2021-05-19 23:10 ` Sean Christopherson
2021-05-21 7:06 ` Maciej S. Szmigiero
2021-05-25 23:21 ` Sean Christopherson
2021-06-01 20:24 ` Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 7/8] KVM: Optimize gfn lookup in kvm_zap_gfn_range() Maciej S. Szmigiero
2021-05-26 17:33 ` Sean Christopherson
2021-06-01 20:25 ` Maciej S. Szmigiero
2021-05-16 21:44 ` [PATCH v3 8/8] KVM: Optimize overlapping memslots check Maciej S. Szmigiero
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=b8258ced64a81c7d90320c2921fe08b11eb47362.1621191551.git.maciej.szmigiero@oracle.com \
--to=mail@maciej.szmigiero.name \
--cc=aleksandar.qemu.devel@gmail.com \
--cc=borntraeger@de.ibm.com \
--cc=chenhuacai@kernel.org \
--cc=cohuck@redhat.com \
--cc=david@redhat.com \
--cc=frankja@linux.ibm.com \
--cc=imammedo@redhat.com \
--cc=imbrenda@linux.ibm.com \
--cc=james.morse@arm.com \
--cc=jmattson@google.com \
--cc=joro@8bytes.org \
--cc=julien.thierry.kdev@gmail.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maz@kernel.org \
--cc=paulus@ozlabs.org \
--cc=pbonzini@redhat.com \
--cc=seanjc@google.com \
--cc=suzuki.poulose@arm.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.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).