From: David Gibson <d...@au1.ibm.com>
This improves I/O performance for guests using the PAPR paravirtualization
interface by making the H_PUT_TCE hcall faster, by implementing it in
real mode. H_PUT_TCE is used for updating virtual IOMMU tables, and is
used both for virtual I/O and for real I/O in the PAPR interface.
Since this moves the IOMMU tables into the kernel, we define a new
KVM_CREATE_SPAPR_TCE ioctl to allow qemu to create the tables.
The ioctl returns a file descriptor which can be used to mmap the
newly created table.
Signed-off-by: Paul Mackerras <pau...@samba.org>
---
arch/powerpc/include/asm/kvm.h | 9 +++
arch/powerpc/include/asm/kvm_book3s_64.h | 2 +
arch/powerpc/include/asm/kvm_host.h | 9 +++
arch/powerpc/include/asm/kvm_ppc.h | 2 +
arch/powerpc/kvm/Makefile | 3 +-
arch/powerpc/kvm/book3s_64_vio_hv.c | 73 +++++++++++++++++++
arch/powerpc/kvm/book3s_hv.c | 116 +++++++++++++++++++++++++++++-
arch/powerpc/kvm/book3s_hv_rmhandlers.S | 2 +-
arch/powerpc/kvm/powerpc.c | 18 +++++
include/linux/kvm.h | 5 ++
10 files changed, 236 insertions(+), 3 deletions(-)
create mode 100644 arch/powerpc/kvm/book3s_64_vio_hv.c
diff --git a/arch/powerpc/include/asm/kvm.h b/arch/powerpc/include/asm/kvm.h
index 18ea696..a9e641b 100644
--- a/arch/powerpc/include/asm/kvm.h
+++ b/arch/powerpc/include/asm/kvm.h
@@ -22,6 +22,9 @@
#include <linux/types.h>
+/* Select powerpc specific features in <linux/kvm.h> */
+#define __KVM_HAVE_SPAPR_TCE
+
struct kvm_regs {
__u64 pc;
__u64 cr;
@@ -88,4 +91,10 @@ struct kvm_guest_debug_arch {
#define KVM_INTERRUPT_UNSET -2U
#define KVM_INTERRUPT_SET_LEVEL -3U
+/* for KVM_CAP_SPAPR_TCE */
+struct kvm_create_spapr_tce {
+ __u64 liobn;
+ __u32 window_size;
+};
+
#endif /* __LINUX_KVM_POWERPC_H */
diff --git a/arch/powerpc/include/asm/kvm_book3s_64.h
b/arch/powerpc/include/asm/kvm_book3s_64.h
index 4cadd61..e1a096b 100644
--- a/arch/powerpc/include/asm/kvm_book3s_64.h
+++ b/arch/powerpc/include/asm/kvm_book3s_64.h
@@ -25,4 +25,6 @@ static inline struct kvmppc_book3s_shadow_vcpu
*to_svcpu(struct kvm_vcpu *vcpu)
return &get_paca()->shadow_vcpu;
}
+#define SPAPR_TCE_SHIFT 12
+
#endif /* __ASM_KVM_BOOK3S_64_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h
b/arch/powerpc/include/asm/kvm_host.h
index af6703e..cda183e 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -144,6 +144,14 @@ struct kvmppc_pginfo {
atomic_t refcnt;
};
+struct kvmppc_spapr_tce_table {
+ struct list_head list;
+ struct kvm *kvm;
+ u64 liobn;
+ u32 window_size;
+ struct page *pages[0];
+};
+
struct kvm_arch {
unsigned long hpt_virt;
unsigned long ram_npages;
@@ -157,6 +165,7 @@ struct kvm_arch {
unsigned long host_sdr1;
int tlbie_lock;
unsigned short last_vcpu[NR_CPUS];
+ struct list_head spapr_tce_tables;
};
struct kvmppc_pte {
diff --git a/arch/powerpc/include/asm/kvm_ppc.h
b/arch/powerpc/include/asm/kvm_ppc.h
index b4ee11a..de683fa 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -117,6 +117,8 @@ extern long kvmppc_prepare_vrma(struct kvm *kvm,
extern void kvmppc_map_vrma(struct kvm *kvm,
struct kvm_userspace_memory_region *mem);
extern int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu);
+extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
+ struct kvm_create_spapr_tce *args);
extern int kvmppc_core_init_vm(struct kvm *kvm);
extern void kvmppc_core_destroy_vm(struct kvm *kvm);
extern int kvmppc_core_prepare_memory_region(struct kvm *kvm,
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 37c1a60..8ba062f 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -59,7 +59,8 @@ kvm-book3s_64_hv-objs := \
book3s.o \
book3s_hv.o \
book3s_hv_interrupts.o \
- book3s_64_mmu_hv.o
+ book3s_64_mmu_hv.o \
+ book3s_64_vio_hv.o
kvm-objs-$(CONFIG_KVM_BOOK3S_64_HV) := $(kvm-book3s_64_hv-objs)
kvm-book3s_32-objs := \
diff --git a/arch/powerpc/kvm/book3s_64_vio_hv.c
b/arch/powerpc/kvm/book3s_64_vio_hv.c
new file mode 100644
index 0000000..ea0f8c5
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_64_vio_hv.c
@@ -0,0 +1,73 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Copyright 2010 Paul Mackerras, IBM Corp. <pau...@au1.ibm.com>
+ * Copyright 2011 David Gibson, IBM Corporation <d...@au1.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/highmem.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/hugetlb.h>
+#include <linux/list.h>
+
+#include <asm/tlbflush.h>
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
+#include <asm/mmu-hash64.h>
+#include <asm/hvcall.h>
+#include <asm/synch.h>
+#include <asm/ppc-opcode.h>
+#include <asm/kvm_host.h>
+#include <asm/udbg.h>
+
+#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
+
+long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
+ unsigned long ioba, unsigned long tce)
+{
+ struct kvm *kvm = vcpu->kvm;
+ struct kvmppc_spapr_tce_table *stt;
+
+ /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
+ /* liobn, ioba, tce); */
+
+ list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
+ if (stt->liobn == liobn) {
+ unsigned long idx = ioba >> SPAPR_TCE_SHIFT;
+ struct page *page;
+ u64 *tbl;
+
+ /* udbg_printf("H_PUT_TCE: liobn 0x%lx => stt=%p
window_size=0x%x\n", */
+ /* liobn, stt, stt->window_size); */
+ if (ioba >= stt->window_size)
+ return H_PARAMETER;
+
+ page = stt->pages[idx / TCES_PER_PAGE];
+ tbl = (u64 *)page_address(page);
+
+ /* FIXME: Need to validate the TCE itself */
+ /* udbg_printf("tce @ %p\n", &tbl[idx %
TCES_PER_PAGE]); */
+ tbl[idx % TCES_PER_PAGE] = tce;
+ return H_SUCCESS;
+ }
+ }
+
+ /* Didn't find the liobn, punt it to userspace */
+ return H_TOO_HARD;
+}
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 377a35a..eed2c10 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -506,6 +506,116 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu
*vcpu)
return r;
}
+static long kvmppc_stt_npages(unsigned long window_size)
+{
+ return ALIGN((window_size >> SPAPR_TCE_SHIFT)
+ * sizeof(u64), PAGE_SIZE) / PAGE_SIZE;
+}
+
+static void release_spapr_tce_table(struct kvmppc_spapr_tce_table *stt)
+{
+ struct kvm *kvm = stt->kvm;
+ int i;
+
+ mutex_lock(&kvm->lock);
+ list_del(&stt->list);
+ for (i = 0; i < kvmppc_stt_npages(stt->window_size); i++)
+ __free_page(stt->pages[i]);
+ kfree(stt);
+ mutex_unlock(&kvm->lock);
+
+ kvm_put_kvm(kvm);
+}
+
+static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault
*vmf)
+{
+ struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
+ struct page *page;
+
+ if (vmf->pgoff >= kvmppc_stt_npages(stt->window_size))
+ return VM_FAULT_SIGBUS;
+
+ page = stt->pages[vmf->pgoff];
+ get_page(page);
+ vmf->page = page;
+ return 0;
+}
+
+static const struct vm_operations_struct kvm_spapr_tce_vm_ops = {
+ .fault = kvm_spapr_tce_fault,
+};
+
+static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &kvm_spapr_tce_vm_ops;
+ return 0;
+}
+
+static int kvm_spapr_tce_release(struct inode *inode, struct file *filp)
+{
+ struct kvmppc_spapr_tce_table *stt = filp->private_data;
+
+ release_spapr_tce_table(stt);
+ return 0;
+}
+
+static struct file_operations kvm_spapr_tce_fops = {
+ .mmap = kvm_spapr_tce_mmap,
+ .release = kvm_spapr_tce_release,
+};
+
+long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
+ struct kvm_create_spapr_tce *args)
+{
+ struct kvmppc_spapr_tce_table *stt = NULL;
+ long npages;
+ int ret = -ENOMEM;
+ int i;
+
+ /* Check this LIOBN hasn't been previously allocated */
+ list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
+ if (stt->liobn == args->liobn)
+ return -EBUSY;
+ }
+
+ npages = kvmppc_stt_npages(args->window_size);
+
+ stt = kzalloc(sizeof(*stt) + npages* sizeof(struct page *),
+ GFP_KERNEL);
+ if (!stt)
+ goto fail;
+
+ stt->liobn = args->liobn;
+ stt->window_size = args->window_size;
+ stt->kvm = kvm;
+
+ for (i = 0; i < npages; i++) {
+ stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!stt->pages[i])
+ goto fail;
+ }
+
+ kvm_get_kvm(kvm);
+
+ mutex_lock(&kvm->lock);
+ list_add(&stt->list, &kvm->arch.spapr_tce_tables);
+
+ mutex_unlock(&kvm->lock);
+
+ return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
+ stt, O_RDONLY);
+
+fail:
+ if (stt) {
+ for (i = 0; i < npages; i++)
+ if (stt->pages[i])
+ __free_page(stt->pages[i]);
+
+ kfree(stt);
+ }
+ return ret;
+}
+
int kvmppc_core_prepare_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem)
{
@@ -527,13 +637,17 @@ int kvmppc_core_init_vm(struct kvm *kvm)
/* Allocate hashed page table */
r = kvmppc_alloc_hpt(kvm);
+ if (r)
+ return r;
- return r;
+ INIT_LIST_HEAD(&kvm->arch.spapr_tce_tables);
+ return 0;
}
void kvmppc_core_destroy_vm(struct kvm *kvm)
{
kvmppc_free_hpt(kvm);
+ WARN_ON(!list_empty(&kvm->arch.spapr_tce_tables));
}
/* These are stubs for now */
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index e8a8f3c..95f6386 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -722,7 +722,7 @@ hcall_real_table:
.long 0 /* 0x14 - H_CLEAR_REF */
.long .kvmppc_h_protect - hcall_real_table
.long 0 /* 0x1c - H_GET_TCE */
- .long 0 /* 0x20 - H_SET_TCE */
+ .long .kvmppc_h_put_tce - hcall_real_table
.long 0 /* 0x24 - H_SET_SPRG0 */
.long .kvmppc_h_set_dabr - hcall_real_table
.long 0 /* 0x2c */
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 7bfe413..10f777a 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -196,6 +196,11 @@ int kvm_dev_ioctl_check_extension(long ext)
r = KVM_COALESCED_MMIO_PAGE_OFFSET;
break;
#endif
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+ case KVM_CAP_SPAPR_TCE:
+ r = 1;
+ break;
+#endif
default:
r = 0;
break;
@@ -628,6 +633,19 @@ long kvm_arch_vm_ioctl(struct file *filp,
break;
}
+#ifdef CONFIG_KVM_BOOK3S_64_HV
+ case KVM_CREATE_SPAPR_TCE: {
+ struct kvm_create_spapr_tce create_tce;
+ struct kvm *kvm = filp->private_data;
+
+ r = -EFAULT;
+ if (copy_from_user(&create_tce, argp, sizeof(create_tce)))
+ goto out;
+ r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce);
+ goto out;
+ }
+#endif /* CONFIG_KVM_BOOK3S_64_HV */
+
default:
r = -ENOTTY;
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index a4447ce..3d3cdf1 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -547,6 +547,9 @@ struct kvm_ppc_pvinfo {
#define KVM_CAP_PPC_GET_PVINFO 57
#define KVM_CAP_PPC_IRQ_LEVEL 58
#define KVM_CAP_ASYNC_PF 59
+#ifdef __KVM_HAVE_SPAPR_TCE
+#define KVM_CAP_SPAPR_TCE 60
+#endif
#ifdef KVM_CAP_IRQ_ROUTING
@@ -746,6 +749,8 @@ struct kvm_clock_data {
/* Available with KVM_CAP_XCRS */
#define KVM_GET_XCRS _IOR(KVMIO, 0xa6, struct kvm_xcrs)
#define KVM_SET_XCRS _IOW(KVMIO, 0xa7, struct kvm_xcrs)
+/* Available with KVM_CAP_SPAPR_TCE */
+#define KVM_CREATE_SPAPR_TCE _IOW(KVMIO, 0xa8, struct
kvm_create_spapr_tce)
#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)
--
1.7.4.4
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