[PATCH kernel v2 4/4] KVM: PPC: Add support for 64bit TCE windows
Alexey Kardashevskiy
aik at ozlabs.ru
Tue Mar 1 17:54:40 AEDT 2016
The existing KVM_CREATE_SPAPR_TCE only supports 32bit windows which is not
enough for directly mapped windows as the guest can get more than 4GB.
This adds KVM_CREATE_SPAPR_TCE_64 ioctl and advertises it
via KVM_CAP_SPAPR_TCE_64 capability. The table size is checked against
the locked memory limit.
Since 64bit windows are to support Dynamic DMA windows (DDW), let's add
@bus_offset and @page_shift which are also required by DDW.
Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
Changes:
v2:
* fixed padding in kvm_create_spapr_tce_64
* added comment in commit log about checking the window size
---
Documentation/virtual/kvm/api.txt | 32 ++++++++++++++++++++++++++++++++
arch/powerpc/include/asm/kvm_ppc.h | 2 +-
arch/powerpc/include/uapi/asm/kvm.h | 9 +++++++++
arch/powerpc/kvm/book3s_64_vio.c | 10 +++++++---
arch/powerpc/kvm/powerpc.c | 25 ++++++++++++++++++++++++-
include/uapi/linux/kvm.h | 2 ++
6 files changed, 75 insertions(+), 5 deletions(-)
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index da39435..bc78652 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -3060,6 +3060,38 @@ an implementation for these despite the in kernel acceleration.
This capability is always enabled.
+4.98 KVM_CREATE_SPAPR_TCE_64
+
+Capability: KVM_CAP_SPAPR_TCE_64
+Architectures: powerpc
+Type: vm ioctl
+Parameters: struct kvm_create_spapr_tce_64 (in)
+Returns: file descriptor for manipulating the created TCE table
+
+This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit
+windows, described in 4.62 KVM_CREATE_SPAPR_TCE
+
+This capability uses extended struct in ioctl interface:
+
+/* for KVM_CAP_SPAPR_TCE_64 */
+struct kvm_create_spapr_tce_64 {
+ __u64 liobn;
+ __u32 page_shift;
+ __u32 flags;
+ __u64 offset; /* in pages */
+ __u64 size; /* in pages */
+};
+
+The aim of extension is to support an additional bigger DMA window with
+a variable page size.
+KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and
+a bus offset of the corresponding DMA window, @size and @offset are numbers
+of IOMMU pages.
+
+ at flags are not used at the moment.
+
+The rest of functionality is identical to KVM_CREATE_SPAPR_TCE.
+
5. The kvm_run structure
------------------------
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 197a8ac..2544eda 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -165,7 +165,7 @@ extern void kvmppc_map_vrma(struct kvm_vcpu *vcpu,
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);
+ struct kvm_create_spapr_tce_64 *args);
extern struct kvmppc_spapr_tce_table *kvmppc_find_table(
struct kvm_vcpu *vcpu, unsigned long liobn);
extern long kvmppc_ioba_validate(struct kvmppc_spapr_tce_table *stt,
diff --git a/arch/powerpc/include/uapi/asm/kvm.h b/arch/powerpc/include/uapi/asm/kvm.h
index ab4d473..c93cf35 100644
--- a/arch/powerpc/include/uapi/asm/kvm.h
+++ b/arch/powerpc/include/uapi/asm/kvm.h
@@ -333,6 +333,15 @@ struct kvm_create_spapr_tce {
__u32 window_size;
};
+/* for KVM_CAP_SPAPR_TCE_64 */
+struct kvm_create_spapr_tce_64 {
+ __u64 liobn;
+ __u32 page_shift;
+ __u32 flags;
+ __u64 offset; /* in pages */
+ __u64 size; /* in pages */
+};
+
/* for KVM_ALLOCATE_RMA */
struct kvm_allocate_rma {
__u64 rma_size;
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 61cbc44..2c2d103 100644
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -147,20 +147,23 @@ static const struct file_operations kvm_spapr_tce_fops = {
};
long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
- struct kvm_create_spapr_tce *args)
+ struct kvm_create_spapr_tce_64 *args)
{
struct kvmppc_spapr_tce_table *stt = NULL;
unsigned long npages, size;
int ret = -ENOMEM;
int i;
+ if (!args->size)
+ return -EINVAL;
+
/* 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;
}
- size = args->window_size >> IOMMU_PAGE_SHIFT_4K;
+ size = args->size;
npages = kvmppc_tce_pages(size);
ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
if (ret) {
@@ -174,7 +177,8 @@ long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
goto fail;
stt->liobn = args->liobn;
- stt->page_shift = IOMMU_PAGE_SHIFT_4K;
+ stt->page_shift = args->page_shift;
+ stt->offset = args->offset;
stt->size = size;
stt->kvm = kvm;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 9258675..19aa59b 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -33,6 +33,7 @@
#include <asm/tlbflush.h>
#include <asm/cputhreads.h>
#include <asm/irqflags.h>
+#include <asm/iommu.h>
#include "timing.h"
#include "irq.h"
#include "../mm/mmu_decl.h"
@@ -519,6 +520,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
#ifdef CONFIG_PPC_BOOK3S_64
case KVM_CAP_SPAPR_TCE:
+ case KVM_CAP_SPAPR_TCE_64:
case KVM_CAP_PPC_ALLOC_HTAB:
case KVM_CAP_PPC_RTAS:
case KVM_CAP_PPC_FIXUP_HCALL:
@@ -1344,13 +1346,34 @@ long kvm_arch_vm_ioctl(struct file *filp,
break;
}
#ifdef CONFIG_PPC_BOOK3S_64
+ case KVM_CREATE_SPAPR_TCE_64: {
+ struct kvm_create_spapr_tce_64 create_tce_64;
+
+ r = -EFAULT;
+ if (copy_from_user(&create_tce_64, argp, sizeof(create_tce_64)))
+ goto out;
+ if (create_tce_64.flags) {
+ r = -EINVAL;
+ goto out;
+ }
+ r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce_64);
+ goto out;
+ }
case KVM_CREATE_SPAPR_TCE: {
struct kvm_create_spapr_tce create_tce;
+ struct kvm_create_spapr_tce_64 create_tce_64;
r = -EFAULT;
if (copy_from_user(&create_tce, argp, sizeof(create_tce)))
goto out;
- r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce);
+
+ create_tce_64.liobn = create_tce.liobn;
+ create_tce_64.page_shift = IOMMU_PAGE_SHIFT_4K;
+ create_tce_64.offset = 0;
+ create_tce_64.size = create_tce.window_size >>
+ IOMMU_PAGE_SHIFT_4K;
+ create_tce_64.flags = 0;
+ r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce_64);
goto out;
}
case KVM_PPC_GET_SMMU_INFO: {
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 8ce5f64..b06208b 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1143,6 +1143,8 @@ struct kvm_s390_ucas_mapping {
/* Available with KVM_CAP_PPC_ALLOC_HTAB */
#define KVM_PPC_ALLOCATE_HTAB _IOWR(KVMIO, 0xa7, __u32)
#define KVM_CREATE_SPAPR_TCE _IOW(KVMIO, 0xa8, struct kvm_create_spapr_tce)
+#define KVM_CREATE_SPAPR_TCE_64 _IOW(KVMIO, 0xa8, \
+ struct kvm_create_spapr_tce_64)
/* Available with KVM_CAP_RMA */
#define KVM_ALLOCATE_RMA _IOR(KVMIO, 0xa9, struct kvm_allocate_rma)
/* Available with KVM_CAP_PPC_HTAB_FD */
--
2.5.0.rc3
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