This is the host side interface that the guests which support KVM TMEM
talk to.
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
arch/x86/kvm/tmem/Kconfig | 6 +++
arch/x86/kvm/tmem/Makefile | 2 +
arch/x86/kvm/tmem/host.c | 78 ++++++++++++++++++++++++++++++++++
arch/x86/kvm/tmem/host.h | 20 +++++++++
arch/x86/kvm/x86.c | 8 +---
drivers/staging/zcache/zcache-main.c | 35 +++++++++++++++-
6 files changed, 141 insertions(+), 8 deletions(-)
create mode 100644 arch/x86/kvm/tmem/host.c
create mode 100644 arch/x86/kvm/tmem/host.h
diff --git a/arch/x86/kvm/tmem/Kconfig b/arch/x86/kvm/tmem/Kconfig
index 15d8301..1a59e4f 100644
--- a/arch/x86/kvm/tmem/Kconfig
+++ b/arch/x86/kvm/tmem/Kconfig
@@ -13,4 +13,10 @@ menuconfig KVM_TMEM
if KVM_TMEM
+config KVM_TMEM_HOST
+ bool "Host-side KVM TMEM"
+ ---help---
+ With this option on, the KVM host will be able to process KVM TMEM requests
+ coming from guests.
+
endif # KVM_TMEM
diff --git a/arch/x86/kvm/tmem/Makefile b/arch/x86/kvm/tmem/Makefile
index 6812d46..706cd36 100644
--- a/arch/x86/kvm/tmem/Makefile
+++ b/arch/x86/kvm/tmem/Makefile
@@ -1 +1,3 @@
ccflags-y += -Idrivers/staging/zcache/
+
+obj-$(CONFIG_KVM_TMEM_HOST) += host.o
diff --git a/arch/x86/kvm/tmem/host.c b/arch/x86/kvm/tmem/host.c
new file mode 100644
index 0000000..9e73395
--- /dev/null
+++ b/arch/x86/kvm/tmem/host.c
@@ -0,0 +1,78 @@
+/*
+ * KVM TMEM host side interface
+ *
+ * Copyright (c) 2012 Sasha Levin
+ *
+ */
+
+#include <linux/kvm_types.h>
+#include <linux/kvm_host.h>
+
+#include "tmem.h"
+#include <zcache.h>
+
+int use_kvm_tmem_host = 1;
+
+static int no_kvmtmemhost(char *s)
+{
+ use_kvm_tmem_host = 0;
+ return 1;
+}
+
+__setup("nokvmtmemhost", no_kvmtmemhost);
+
+int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret)
+{
+ struct tmem_kvm_op op;
+ struct page *page;
+ int r;
+ unsigned long flags;
+
+ if (!use_kvm_tmem_host || !zcache_enabled) {
+ *ret = -ENXIO;
+ return 0;
+ }
+
+ r = kvm_read_guest(vcpu->kvm, addr, &op, sizeof(op));
+ if (r < 0) {
+ *ret = r;
+ return 0;
+ }
+
+ switch (op.cmd) {
+ case TMEM_NEW_POOL:
+ *ret = zcache_new_pool(op.cli_id, op.u.new.flags);
+ break;
+ case TMEM_DESTROY_POOL:
+ *ret = zcache_destroy_pool(op.cli_id, op.pool_id);
+ break;
+ case TMEM_NEW_PAGE:
+ break;
+ case TMEM_PUT_PAGE:
+ page = gfn_to_page(vcpu->kvm, op.u.gen.gfn);
+ local_irq_save(flags);
+ *ret = zcache_put_page(op.cli_id, op.pool_id,
+ &op.u.gen.oid, op.u.gen.index, page);
+ local_irq_restore(flags);
+ break;
+ case TMEM_GET_PAGE:
+ page = gfn_to_page(vcpu->kvm, op.u.gen.gfn);
+ local_irq_save(flags);
+ *ret = zcache_get_page(op.cli_id, op.pool_id,
+ &op.u.gen.oid, op.u.gen.index, page);
+ local_irq_restore(flags);
+ break;
+ case TMEM_FLUSH_PAGE:
+ local_irq_save(flags);
+ *ret = zcache_flush_page(op.cli_id, op.pool_id,
+ &op.u.gen.oid, op.u.gen.index);
+ local_irq_restore(flags);
+ break;
+ case TMEM_FLUSH_OBJECT:
+ local_irq_save(flags);
+ *ret = zcache_flush_object(op.cli_id, op.pool_id, &op.u.gen.oid);
+ local_irq_restore(flags);
+ break;
+ }
+ return 0;
+}
diff --git a/arch/x86/kvm/tmem/host.h b/arch/x86/kvm/tmem/host.h
new file mode 100644
index 0000000..17ba0c4
--- /dev/null
+++ b/arch/x86/kvm/tmem/host.h
@@ -0,0 +1,20 @@
+#ifndef _KVM_TMEM_HOST_H_
+#define _KVM_TMEM_HOST_H_
+
+#ifdef CONFIG_KVM_TMEM_HOST
+
+extern int use_kvm_tmem_host;
+
+extern int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret);
+
+#else
+
+static inline int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret)
+{
+ *ret = -ENOSUPP;
+ return 0;
+}
+
+#endif
+
+#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4c5b6ab..c92d4c8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -27,6 +27,7 @@
#include "kvm_cache_regs.h"
#include "x86.h"
#include "cpuid.h"
+#include "tmem/host.h"
#include <linux/clocksource.h>
#include <linux/interrupt.h>
@@ -4993,13 +4994,6 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
return 1;
}
-static int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret)
-{
- *ret = -ENOTSUPP;
-
- return 0;
-}
-
static inline gpa_t hc_gpa(struct kvm_vcpu *vcpu, unsigned long a0,
unsigned long a1)
{
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index a196aff..65c0ab0 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -1692,7 +1692,7 @@ out:
return ret;
}
-static int zcache_new_pool(uint16_t cli_id, uint32_t flags)
+int zcache_new_pool(uint16_t cli_id, uint32_t flags)
{
int poolid = -1;
struct tmem_pool *pool;
@@ -2011,6 +2011,37 @@ out:
return ret;
}
+#ifdef CONFIG_KVM_TMEM_HOST
+extern int use_kvm_tmem_host;
+
+static int __zcache_init_kvm(void)
+{
+ int ret = 0;
+
+ if (use_kvm_tmem_host) {
+ ret = zcache_new_client(KVM_CLIENT);
+ if (ret) {
+ pr_err("zcache: can't create client\n");
+ return -1;
+ } else {
+ pr_info("zcache: enabled support for KVM TMEM\n");
+ }
+ }
+ zbud_init();
+ register_shrinker(&zcache_shrinker);
+
+ return 0;
+}
+
+#else
+
+static inline int static int __zcache_init_kvm(void)
+{
+ return 0;
+}
+
+#endif
+
static int __init zcache_init(void)
{
int ret = 0;
@@ -2053,6 +2084,8 @@ static int __init zcache_init(void)
pr_err("zcache: can't create client\n");
goto out;
}
+ if (__zcache_init_kvm())
+ goto out;
#endif
#ifdef CONFIG_CLEANCACHE
if (zcache_enabled && use_cleancache) {
--
1.7.8.6
--
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