KVM: arm64: vgic-its: Device table save/restore

This patch saves the device table entries into guest RAM.
Both flat table and 2 stage tables are supported. DeviceId
indexing is used.

For each device listed in the device table, we also save
the translation table using the vgic_its_save/restore_itt
routines. Those functions will be implemented in a subsequent
patch.

On restore, devices are re-allocated and their itt are
re-built.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
This commit is contained in:
Eric Auger 2017-01-09 16:27:07 +01:00 committed by Christoffer Dall
parent dceff70258
commit 57a9a11715
2 changed files with 199 additions and 5 deletions

View File

@ -23,6 +23,7 @@
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/uaccess.h>
#include <linux/list_sort.h>
#include <linux/irqchip/arm-gic-v3.h>
@ -1735,7 +1736,8 @@ out:
return ret;
}
u32 compute_next_devid_offset(struct list_head *h, struct its_device *dev)
static u32 compute_next_devid_offset(struct list_head *h,
struct its_device *dev)
{
struct its_device *next;
u32 next_offset;
@ -1789,8 +1791,8 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry,
* Return: < 0 on error, 0 if last element was identified, 1 otherwise
* (the last element may not be found on second level tables)
*/
int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
int start_id, entry_fn_t fn, void *opaque)
static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
int start_id, entry_fn_t fn, void *opaque)
{
void *entry = kzalloc(esz, GFP_KERNEL);
struct kvm *kvm = its->dev->kvm;
@ -1825,13 +1827,171 @@ out:
return ret;
}
static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device)
{
return -ENXIO;
}
static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev)
{
return -ENXIO;
}
/**
* vgic_its_save_dte - Save a device table entry at a given GPA
*
* @its: ITS handle
* @dev: ITS device
* @ptr: GPA
*/
static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev,
gpa_t ptr, int dte_esz)
{
struct kvm *kvm = its->dev->kvm;
u64 val, itt_addr_field;
u32 next_offset;
itt_addr_field = dev->itt_addr >> 8;
next_offset = compute_next_devid_offset(&its->device_list, dev);
val = (1ULL << KVM_ITS_DTE_VALID_SHIFT |
((u64)next_offset << KVM_ITS_DTE_NEXT_SHIFT) |
(itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) |
(dev->num_eventid_bits - 1));
val = cpu_to_le64(val);
return kvm_write_guest(kvm, ptr, &val, dte_esz);
}
/**
* vgic_its_restore_dte - restore a device table entry
*
* @its: its handle
* @id: device id the DTE corresponds to
* @ptr: kernel VA where the 8 byte DTE is located
* @opaque: unused
*
* Return: < 0 on error, 0 if the dte is the last one, id offset to the
* next dte otherwise
*/
static int vgic_its_restore_dte(struct vgic_its *its, u32 id,
void *ptr, void *opaque)
{
struct its_device *dev;
gpa_t itt_addr;
u8 num_eventid_bits;
u64 entry = *(u64 *)ptr;
bool valid;
u32 offset;
int ret;
entry = le64_to_cpu(entry);
valid = entry >> KVM_ITS_DTE_VALID_SHIFT;
num_eventid_bits = (entry & KVM_ITS_DTE_SIZE_MASK) + 1;
itt_addr = ((entry & KVM_ITS_DTE_ITTADDR_MASK)
>> KVM_ITS_DTE_ITTADDR_SHIFT) << 8;
if (!valid)
return 1;
/* dte entry is valid */
offset = (entry & KVM_ITS_DTE_NEXT_MASK) >> KVM_ITS_DTE_NEXT_SHIFT;
dev = vgic_its_alloc_device(its, id, itt_addr, num_eventid_bits);
if (IS_ERR(dev))
return PTR_ERR(dev);
ret = vgic_its_restore_itt(its, dev);
if (ret)
return ret;
return offset;
}
static int vgic_its_device_cmp(void *priv, struct list_head *a,
struct list_head *b)
{
struct its_device *deva = container_of(a, struct its_device, dev_list);
struct its_device *devb = container_of(b, struct its_device, dev_list);
if (deva->device_id < devb->device_id)
return -1;
else
return 1;
}
/**
* vgic_its_save_device_tables - Save the device table and all ITT
* into guest RAM
*
* L1/L2 handling is hidden by vgic_its_check_id() helper which directly
* returns the GPA of the device entry
*/
static int vgic_its_save_device_tables(struct vgic_its *its)
{
return -ENXIO;
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
struct its_device *dev;
int dte_esz = abi->dte_esz;
u64 baser;
baser = its->baser_device_table;
list_sort(NULL, &its->device_list, vgic_its_device_cmp);
list_for_each_entry(dev, &its->device_list, dev_list) {
int ret;
gpa_t eaddr;
if (!vgic_its_check_id(its, baser,
dev->device_id, &eaddr))
return -EINVAL;
ret = vgic_its_save_itt(its, dev);
if (ret)
return ret;
ret = vgic_its_save_dte(its, dev, eaddr, dte_esz);
if (ret)
return ret;
}
return 0;
}
/**
* handle_l1_dte - callback used for L1 device table entries (2 stage case)
*
* @its: its handle
* @id: index of the entry in the L1 table
* @addr: kernel VA
* @opaque: unused
*
* L1 table entries are scanned by steps of 1 entry
* Return < 0 if error, 0 if last dte was found when scanning the L2
* table, +1 otherwise (meaning next L1 entry must be scanned)
*/
static int handle_l1_dte(struct vgic_its *its, u32 id, void *addr,
void *opaque)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
int l2_start_id = id * (SZ_64K / abi->dte_esz);
u64 entry = *(u64 *)addr;
int dte_esz = abi->dte_esz;
gpa_t gpa;
int ret;
entry = le64_to_cpu(entry);
if (!(entry & KVM_ITS_L1E_VALID_MASK))
return 1;
gpa = entry & KVM_ITS_L1E_ADDR_MASK;
ret = scan_its_table(its, gpa, SZ_64K, dte_esz,
l2_start_id, vgic_its_restore_dte, NULL);
if (ret <= 0)
return ret;
return 1;
}
/**
@ -1840,7 +2000,31 @@ static int vgic_its_save_device_tables(struct vgic_its *its)
*/
static int vgic_its_restore_device_tables(struct vgic_its *its)
{
return -ENXIO;
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
u64 baser = its->baser_device_table;
int l1_esz, ret;
int l1_tbl_size = GITS_BASER_NR_PAGES(baser) * SZ_64K;
gpa_t l1_gpa;
if (!(baser & GITS_BASER_VALID))
return 0;
l1_gpa = BASER_ADDRESS(baser);
if (baser & GITS_BASER_INDIRECT) {
l1_esz = GITS_LVL1_ENTRY_SIZE;
ret = scan_its_table(its, l1_gpa, l1_tbl_size, l1_esz, 0,
handle_l1_dte, NULL);
} else {
l1_esz = abi->dte_esz;
ret = scan_its_table(its, l1_gpa, l1_tbl_size, l1_esz, 0,
vgic_its_restore_dte, NULL);
}
if (ret > 0)
ret = -EINVAL;
return ret;
}
static int vgic_its_save_cte(struct vgic_its *its,

View File

@ -81,6 +81,16 @@
#define KVM_ITS_CTE_VALID_MASK BIT_ULL(63)
#define KVM_ITS_CTE_RDBASE_SHIFT 16
#define KVM_ITS_CTE_ICID_MASK GENMASK_ULL(15, 0)
#define KVM_ITS_DTE_VALID_SHIFT 63
#define KVM_ITS_DTE_VALID_MASK BIT_ULL(63)
#define KVM_ITS_DTE_NEXT_SHIFT 49
#define KVM_ITS_DTE_NEXT_MASK GENMASK_ULL(62, 49)
#define KVM_ITS_DTE_ITTADDR_SHIFT 5
#define KVM_ITS_DTE_ITTADDR_MASK GENMASK_ULL(48, 5)
#define KVM_ITS_DTE_SIZE_MASK GENMASK_ULL(4, 0)
#define KVM_ITS_L1E_VALID_MASK BIT_ULL(63)
/* we only support 64 kB translation table page size */
#define KVM_ITS_L1E_ADDR_MASK GENMASK_ULL(51, 16)
static inline bool irq_is_pending(struct vgic_irq *irq)
{