From: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
virtualization@lists.linux-foundation.org,
linux-s390@vger.kernel.org,
xen-devel-request@lists.xenproject.org, kvm@vger.kernel.org,
xen-devel@lists.xenproject.org, x86@kernel.org
Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
mingo@redhat.com, peterz@infradead.org,
paulmck@linux.vnet.ibm.com, will.deacon@arm.com,
kernellwp@gmail.com, jgross@suse.com, pbonzini@redhat.com,
bsingharora@gmail.com, boqun.feng@gmail.com,
borntraeger@de.ibm.com, rkrcmar@redhat.com,
David.Laight@ACULAB.COM, dave@stgolabs.net,
konrad.wilk@oracle.com,
Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Subject: [PATCH v7 07/11] KVM: Introduce kvm_write_guest_offset_cached
Date: Wed, 2 Nov 2016 05:08:34 -0400 [thread overview]
Message-ID: <1478077718-37424-8-git-send-email-xinhui.pan@linux.vnet.ibm.com> (raw)
In-Reply-To: <1478077718-37424-1-git-send-email-xinhui.pan@linux.vnet.ibm.com>
It allows us to update some status or field of one struct partially.
We can also save one kvm_read_guest_cached if we just update one filed
of the struct regardless of its current value.
Signed-off-by: Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/linux/kvm_host.h | 2 ++
virt/kvm/kvm_main.c | 20 ++++++++++++++------
2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 01c0b9c..6f00237 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -645,6 +645,8 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
unsigned long len);
int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
void *data, unsigned long len);
+int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+ void *data, int offset, unsigned long len);
int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
gpa_t gpa, unsigned long len);
int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2907b7b..95308ee 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1972,30 +1972,38 @@ int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
}
EXPORT_SYMBOL_GPL(kvm_gfn_to_hva_cache_init);
-int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
- void *data, unsigned long len)
+int kvm_write_guest_offset_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+ void *data, int offset, unsigned long len)
{
struct kvm_memslots *slots = kvm_memslots(kvm);
int r;
+ gpa_t gpa = ghc->gpa + offset;
- BUG_ON(len > ghc->len);
+ BUG_ON(len + offset > ghc->len);
if (slots->generation != ghc->generation)
kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa, ghc->len);
if (unlikely(!ghc->memslot))
- return kvm_write_guest(kvm, ghc->gpa, data, len);
+ return kvm_write_guest(kvm, gpa, data, len);
if (kvm_is_error_hva(ghc->hva))
return -EFAULT;
- r = __copy_to_user((void __user *)ghc->hva, data, len);
+ r = __copy_to_user((void __user *)ghc->hva + offset, data, len);
if (r)
return -EFAULT;
- mark_page_dirty_in_slot(ghc->memslot, ghc->gpa >> PAGE_SHIFT);
+ mark_page_dirty_in_slot(ghc->memslot, gpa >> PAGE_SHIFT);
return 0;
}
+EXPORT_SYMBOL_GPL(kvm_write_guest_offset_cached);
+
+int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
+ void *data, unsigned long len)
+{
+ return kvm_write_guest_offset_cached(kvm, ghc, data, 0, len);
+}
EXPORT_SYMBOL_GPL(kvm_write_guest_cached);
int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
--
2.4.11
next prev parent reply other threads:[~2016-11-02 5:14 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-02 9:08 [PATCH v7 00/11] implement vcpu preempted check Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 01/11] kernel/sched: introduce vcpu preempted check interface Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 02/11] locking/osq: Drop the overload of osq_lock() Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 03/11] kernel/locking: Drop the overload of {mutex, rwsem}_spin_on_owner Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 04/11] powerpc/spinlock: support vcpu preempted check Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 05/11] s390/spinlock: Provide vcpu_is_preempted Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 06/11] x86, paravirt: Add interface to support kvm/xen vcpu preempted check Pan Xinhui
2016-11-15 15:47 ` Peter Zijlstra
2016-11-16 4:19 ` Pan Xinhui
2016-11-16 10:23 ` Peter Zijlstra
2016-11-16 11:29 ` Christian Borntraeger
2016-11-16 11:43 ` Peter Zijlstra
2016-11-17 5:16 ` Pan Xinhui
2016-11-02 9:08 ` Pan Xinhui [this message]
2016-11-02 9:08 ` [PATCH v7 08/11] x86, kvm/x86.c: support " Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 09/11] x86, kernel/kvm.c: " Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 10/11] x86, xen: " Pan Xinhui
2016-11-02 9:08 ` [PATCH v7 11/11] Documentation: virtual: kvm: Support " Pan Xinhui
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