Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1341724
| From | Xiao Guangrong <guangrong.xiao@linux.intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH 04/11] KVM: page track: add the framework of guest page tracking |
| Date | 2016-02-24 11:10 +0100 |
| Message-ID | <r5Eyn-2WS-53@gated-at.bofh.it> (permalink) |
| References | <r5EoG-2C6-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
The array, gfn_track[mode][gfn], is introduced in memory slot for every
guest page, this is the tracking count for the gust page on different
modes. If the page is tracked then the count is increased, the page is
not tracked after the count reaches zero
We use 'unsigned short' as the tracking count which should be enough as
shadow page table only can use 2^14 (2^3 for level, 2^1 for cr4_pae, 2^2
for quadrant, 2^3 for access, 2^1 for nxe, 2^1 for cr0_wp, 2^1 for
smep_andnot_wp, 2^1 for smap_andnot_wp, and 2^1 for smm) at most, there
is enough room for other trackers
Two callbacks, kvm_page_track_create_memslot() and
kvm_page_track_free_memslot() are implemented in this patch, they are
internally used to initialize and reclaim the memory of the array
Currently, only write track mode is supported
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
---
arch/x86/include/asm/kvm_host.h | 10 +++++++
arch/x86/include/asm/kvm_page_track.h | 13 +++++++++
arch/x86/kvm/Makefile | 3 +-
arch/x86/kvm/page_track.c | 52 +++++++++++++++++++++++++++++++++++
arch/x86/kvm/x86.c | 5 ++++
5 files changed, 82 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/include/asm/kvm_page_track.h
create mode 100644 arch/x86/kvm/page_track.c
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1f7fed5..71e43fe 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -32,6 +32,7 @@
#include <asm/mtrr.h>
#include <asm/msr-index.h>
#include <asm/asm.h>
+#include <asm/kvm_page_track.h>
#define KVM_MAX_VCPUS 255
#define KVM_SOFT_MAX_VCPUS 160
@@ -214,6 +215,14 @@ struct kvm_mmu_memory_cache {
void *objects[KVM_NR_MEM_OBJS];
};
+/*
+ * the pages used as guest page table on soft mmu are tracked by
+ * kvm_memory_slot.arch.gfn_track which is 16 bits, so the role bits used
+ * by indirect shadow page can not be more than 15 bits.
+ *
+ * Currently, we used 14 bits that are @level, @cr4_pae, @quadrant, @access,
+ * @nxe, @cr0_wp, @smep_andnot_wp and @smap_andnot_wp.
+ */
union kvm_mmu_page_role {
unsigned word;
struct {
@@ -650,6 +659,7 @@ struct kvm_lpage_info {
struct kvm_arch_memory_slot {
struct kvm_rmap_head *rmap[KVM_NR_PAGE_SIZES];
struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1];
+ unsigned short *gfn_track[KVM_PAGE_TRACK_MAX];
};
/*
diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h
new file mode 100644
index 0000000..55200406
--- /dev/null
+++ b/arch/x86/include/asm/kvm_page_track.h
@@ -0,0 +1,13 @@
+#ifndef _ASM_X86_KVM_PAGE_TRACK_H
+#define _ASM_X86_KVM_PAGE_TRACK_H
+
+enum kvm_page_track_mode {
+ KVM_PAGE_TRACK_WRITE,
+ KVM_PAGE_TRACK_MAX,
+};
+
+void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
+ struct kvm_memory_slot *dont);
+int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
+ unsigned long npages);
+#endif
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index a1ff508..464fa47 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -13,9 +13,10 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o
kvm-y += x86.o mmu.o emulate.o i8259.o irq.o lapic.o \
i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \
- hyperv.o
+ hyperv.o page_track.o
kvm-$(CONFIG_KVM_DEVICE_ASSIGNMENT) += assigned-dev.o iommu.o
+
kvm-intel-y += vmx.o pmu_intel.o
kvm-amd-y += svm.o pmu_amd.o
diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c
new file mode 100644
index 0000000..8c396d0
--- /dev/null
+++ b/arch/x86/kvm/page_track.c
@@ -0,0 +1,52 @@
+/*
+ * Support KVM gust page tracking
+ *
+ * This feature allows us to track page access in guest. Currently, only
+ * write access is tracked.
+ *
+ * Copyright(C) 2015 Intel Corporation.
+ *
+ * Author:
+ * Xiao Guangrong <guangrong.xiao@linux.intel.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ */
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_host.h>
+#include <asm/kvm_page_track.h>
+
+#include "mmu.h"
+
+void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
+ struct kvm_memory_slot *dont)
+{
+ int i;
+
+ for (i = 0; i < KVM_PAGE_TRACK_MAX; i++)
+ if (!dont || free->arch.gfn_track[i] !=
+ dont->arch.gfn_track[i]) {
+ kvfree(free->arch.gfn_track[i]);
+ free->arch.gfn_track[i] = NULL;
+ }
+}
+
+int kvm_page_track_create_memslot(struct kvm_memory_slot *slot,
+ unsigned long npages)
+{
+ int i;
+
+ for (i = 0; i < KVM_PAGE_TRACK_MAX; i++) {
+ slot->arch.gfn_track[i] = kvm_kvzalloc(npages *
+ sizeof(*slot->arch.gfn_track[i]));
+ if (!slot->arch.gfn_track[i])
+ goto track_free;
+ }
+
+ return 0;
+
+track_free:
+ kvm_page_track_free_memslot(slot, NULL);
+ return -ENOMEM;
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 668625e..7b4cfea 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7871,6 +7871,8 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
free->arch.lpage_info[i - 1] = NULL;
}
}
+
+ kvm_page_track_free_memslot(free, dont);
}
int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
@@ -7919,6 +7921,9 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
}
}
+ if (kvm_page_track_create_memslot(slot, npages))
+ goto out_free;
+
return 0;
out_free:
--
1.8.3.1
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
[PATCH v4 00/11] KVM: x86: track guest page access Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:00 +0100
[PATCH 11/11] KVM: MMU: apply page track notifier Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 05/11] KVM: page track: introduce kvm_slot_page_track_{add,remove}_page Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 09/11] KVM: MMU: use page track for non-leaf shadow pages Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
Re: [PATCH 09/11] KVM: MMU: use page track for non-leaf shadow pages Paolo Bonzini <pbonzini@redhat.com> - 2016-02-29 16:30 +0100
[PATCH 10/11] KVM: MMU: simplify mmu_need_write_protect Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 04/11] KVM: page track: add the framework of guest page tracking Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 06/11] KVM: MMU: let page fault handler be aware tracked page Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 08/11] KVM: page track: add notifier support Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 07/11] KVM: MMU: clear write-flooding on the fast path of tracked page Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 01/11] KVM: MMU: rename has_wrprotected_page to mmu_gfn_lpage_is_disallowed Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 11:10 +0100
[PATCH 02/11] KVM: MMU: introduce kvm_mmu_gfn_{allow,disallow}_lpage Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 12:30 +0100
[PATCH 03/11] KVM: MMU: introduce kvm_mmu_slot_gfn_write_protect Xiao Guangrong <guangrong.xiao@linux.intel.com> - 2016-02-24 12:30 +0100
Re: [PATCH v4 00/11] KVM: x86: track guest page access Paolo Bonzini <pbonzini@redhat.com> - 2016-02-24 14:50 +0100
csiph-web