On 17/12/2018 10:31, Julien Thierry wrote:
> Hi,
>
> On 14/12/2018 18:09, Andre Przywara wrote:
>> On Tue, 4 Dec 2018 11:14:33 +0000
>> Julien Thierry <julien.thierry@xxxxxxx> wrote:
>>
>> Hi,
>>
>>> Add an option to let user load files as non-volatile memory.
>>>
>>> An additional range of addresses is reserved for nv memory.
>>> Loaded files must be a multiple of the system page size.
>>>
>>> Users can chose whether the data written by the guest modifies the
>>> original file.
>>>
>>> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
>>> ---
>>> arm/fdt.c | 43 ++++++++++
>>> arm/include/arm-common/kvm-arch.h | 5 +-
>>> arm/include/arm-common/kvm-config-arch.h | 18 ++++-
>>> arm/kvm.c | 134
>>> +++++++++++++++++++++++++++++++ 4 files changed, 198 insertions(+), 2
>>> deletions(-)
>>>
>>> diff --git a/arm/fdt.c b/arm/fdt.c
>>> index 2936986..fd482ce 100644
>>> --- a/arm/fdt.c
>>> +++ b/arm/fdt.c
>>> @@ -72,6 +72,46 @@ static void generate_irq_prop(void *fdt, u8 irq,
>>> enum irq_type irq_type) _FDT(fdt_property(fdt, "interrupts",
>>> irq_prop, sizeof(irq_prop))); }
>>>
>>> +static void generate_nvmem_node(void *fdt, struct kvm_nv_mem *nvmem)
>>> +{
>>> + char *buf;
>>> + int len;
>>> + const u64 reg_prop[] = {
>>> + cpu_to_fdt64(nvmem->map_addr),
>>> + cpu_to_fdt64(nvmem->size)
>>> + };
>>> +
>>> + /* Name length + '@' + 8 hex characters + '\0' */
>>> + len = strlen(nvmem->name) + 10;
>>> + buf = malloc(len);
>>> + snprintf(buf, len, "%s@%llx", nvmem->name,
>>> + nvmem->map_addr);
>>> + _FDT(fdt_begin_node(fdt, buf));
>>> + free(buf);
>>> +
>>> + /* Name length + "kvmtool," + '\0' */
>>> + len = strlen(nvmem->name) + 9;
>>> + buf = malloc(len);
>>> + snprintf(buf, len, "kvmtool,%s", nvmem->name);
>>> + _FDT(fdt_property_string(fdt, "compatible", buf));
>>
>> As discussed in person, it doesn't sound right to (ab)use the
>> compatible name for this. This one should describe a device type, not
>> an instance of it.
>> So I would suggest to use a fixed compatible name (say:
>> "kvmtool,flash"), then put the designator in a property.
>> flash@7f000000 {
>> compatible = "kvmtool,flash";
>> label = "environment";
>> reg = <0 0x7f000000 0 0x10000>;
>> };
>
> Yes, that sounds better than the current situation. Thanks for the
> suggestion.
>
>> So the label property would reflect the user provided name.
>> Also there is the generic "read-only" property, which we might want to
>> use in case "wb" is not provided.
>>
>
> So, I was not really seeing the "wb" as "the guest shouldn't write to
> this", but rather "do you want the file to be updated by what the guest
> writes?".
>
> I was more thinking about the case where you want to start guests with
> the same starting data multiple times, without having to back up your
> data files.
>
> Does that make sense?
Yes, you are right, those are indeed two separate concepts.
Cheers,
Andre
>> I am not overly happy with inventing a new compatible name for such a
>> generic device, but couldn't find anything better (mtd-ram, mtd-rom,
>> cfi-flash were close, but not a complete fit). Also given that the idea
>> is to just communicate this from kvmtool to EDK II (without Linux ever
>> picking this up), I guess this solution works.
>>
>> Cheers,
>> Andre,
>>
>>> + free(buf);
>>> +
>>> + _FDT(fdt_property(fdt, "reg", reg_prop, sizeof(reg_prop)));
>>> +
>>> + _FDT(fdt_end_node(fdt));
>>> +}
>>> +
>>> +static void generate_nvmem_nodes(void *fdt, struct kvm *kvm)
>>> +{
>>> + struct list_head *nvmem_node;
>>> +
>>> + list_for_each(nvmem_node, &kvm->cfg.arch.nvmem_list)
>>> + generate_nvmem_node(fdt,
>>> + container_of(nvmem_node,
>>> + struct kvm_nv_mem,
>>> + node));
>>> +}
>>> +
>>> struct psci_fns {
>>> u32 cpu_suspend;
>>> u32 cpu_off;
>>> @@ -210,6 +250,9 @@ static int setup_fdt(struct kvm *kvm)
>>> _FDT(fdt_property_cell(fdt, "migrate", fns->migrate));
>>> _FDT(fdt_end_node(fdt));
>>>
>>> + /* Non volatile memories */
>>> + generate_nvmem_nodes(fdt, kvm);
>>> +
>>> /* Finalise. */
>>> _FDT(fdt_end_node(fdt));
>>> _FDT(fdt_finish(fdt));
>>> diff --git a/arm/include/arm-common/kvm-arch.h
>>> b/arm/include/arm-common/kvm-arch.h index b9d486d..f425d86 100644
>>> --- a/arm/include/arm-common/kvm-arch.h
>>> +++ b/arm/include/arm-common/kvm-arch.h
>>> @@ -10,6 +10,7 @@
>>> #define ARM_IOPORT_AREA _AC(0x0000000000000000, UL)
>>> #define ARM_MMIO_AREA _AC(0x0000000000010000, UL)
>>> #define ARM_AXI_AREA _AC(0x0000000040000000, UL)
>>> +#define ARM_NVRAM_AREA _AC(0x000000007f000000, UL)
>>> #define ARM_MEMORY_AREA _AC(0x0000000080000000, UL)
>>>
>>> #define ARM_LOMAP_MAX_MEMORY ((1ULL << 32) - ARM_MEMORY_AREA)
>>> @@ -24,9 +25,11 @@
>>> #define ARM_IOPORT_SIZE (ARM_MMIO_AREA -
>>> ARM_IOPORT_AREA) #define ARM_VIRTIO_MMIO_SIZE (ARM_AXI_AREA -
>>> (ARM_MMIO_AREA + ARM_GIC_SIZE)) #define ARM_PCI_CFG_SIZE (1ULL
>>> << 24) -#define ARM_PCI_MMIO_SIZE (ARM_MEMORY_AREA - \
>>> +#define ARM_PCI_MMIO_SIZE (ARM_NVRAM_AREA - \
>>> (ARM_AXI_AREA + ARM_PCI_CFG_SIZE))
>>>
>>> +#define ARM_NVRAM_SIZE (ARM_MEMORY_AREA -
>>> ARM_NVRAM_AREA) +
>>> #define KVM_IOPORT_AREA ARM_IOPORT_AREA
>>> #define KVM_PCI_CFG_AREA ARM_AXI_AREA
>>> #define KVM_PCI_MMIO_AREA (KVM_PCI_CFG_AREA +
>>> ARM_PCI_CFG_SIZE) diff --git
>>> a/arm/include/arm-common/kvm-config-arch.h
>>> b/arm/include/arm-common/kvm-config-arch.h index 5734c46..d5742cb
>>> 100644 --- a/arm/include/arm-common/kvm-config-arch.h +++
>>> b/arm/include/arm-common/kvm-config-arch.h @@ -1,8 +1,18 @@
>>> #ifndef ARM_COMMON__KVM_CONFIG_ARCH_H
>>> #define ARM_COMMON__KVM_CONFIG_ARCH_H
>>>
>>> +#include <linux/list.h>
>>> #include "kvm/parse-options.h"
>>>
>>> +struct kvm_nv_mem {
>>> + char *data_file;
>>> + char *name;
>>> + ssize_t size;
>>> + u64 map_addr;
>>> + bool write_back;
>>> + struct list_head node;
>>> +};
>>> +
>>> struct kvm_config_arch {
>>> const char *dump_dtb_filename;
>>> unsigned int force_cntfrq;
>>> @@ -12,9 +22,11 @@ struct kvm_config_arch {
>>> u64 kaslr_seed;
>>> enum irqchip_type irqchip;
>>> u64 fw_addr;
>>> + struct list_head nvmem_list;
>>> };
>>>
>>> int irqchip_parser(const struct option *opt, const char *arg, int
>>> unset); +int nvmem_parser(const struct option *opt, const char *arg,
>>> int unset);
>>> #define OPT_ARCH_RUN(pfx,
>>> cfg) \
>>> pfx,
>>> \ @@ -33,6 +45,10 @@ int irqchip_parser(const struct option *opt,
>>> const char *arg, int unset); "Type of interrupt controller to emulate
>>> in the guest", \ irqchip_parser,
>>> NULL), \ OPT_U64('\0',
>>> "firmware-address", &(cfg)->fw_addr, \
>>> - "Address where firmware should be loaded"),
>>> + "Address where firmware should be
>>> loaded"), \
>>> + OPT_CALLBACK('\0', "nvmem",
>>> NULL, \
>>> +
>>> "<file>,<name>[,wb]", \
>>> + "Load <file> as non-volatile memory
>>> kvmtool,<name>", \
>>> + nvmem_parser, kvm),
>>>
>>> #endif /* ARM_COMMON__KVM_CONFIG_ARCH_H */
>>> diff --git a/arm/kvm.c b/arm/kvm.c
>>> index 1a2cfdc..00675d9 100644
>>> --- a/arm/kvm.c
>>> +++ b/arm/kvm.c
>>> @@ -18,6 +18,53 @@ struct kvm_ext kvm_req_ext[] = {
>>> { 0, 0 },
>>> };
>>>
>>> +int nvmem_parser(const struct option *opt, const char *arg, int
>>> unset) +{
>>> + struct kvm *kvm = (struct kvm*) opt->ptr;
>>> + struct kvm_nv_mem *nvmem;
>>> + struct stat st;
>>> + const char *ptr;
>>> + uint32_t len;
>>> +
>>> + nvmem = calloc(sizeof (*nvmem), 1);
>>> +
>>> + if (!nvmem)
>>> + die("nvmem: cannot add non-volatile memory");
>>> +
>>> + ptr = strstr(arg, ",");
>>> +
>>> + if (!ptr)
>>> + die("nvmem: missing name for non-volatile memory");
>>> +
>>> + len = ptr - arg + 1;
>>> + nvmem->data_file = malloc(len);
>>> + strncpy(nvmem->data_file, arg, len);
>>> + nvmem->data_file[len - 1] = '\0';
>>> +
>>> + if (stat(nvmem->data_file, &st))
>>> + die("nvmem: failed to stat data file");
>>> + nvmem->size = st.st_size;
>>> +
>>> + arg = arg + len;
>>> + for (ptr = arg; *ptr != '\0' && *ptr != ','; ++ptr)
>>> + ;
>>> + len = ptr - arg + 1;
>>> + nvmem->name = malloc(len);
>>> + strncpy(nvmem->name, arg, len);
>>> + nvmem->name[len - 1] = '\0';
>>> +
>>> + if (*ptr == ',') {
>>> + if (!strcmp(ptr + 1, "wb"))
>>> + nvmem->write_back = true;
>>> + else
>>> + die("firmware-data: invalid option %s", ptr
>>> + 1);
>>> + }
>>> +
>>> + list_add(&nvmem->node, &kvm->cfg.arch.nvmem_list);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> bool kvm__arch_cpu_supports_vm(void)
>>> {
>>> /* The KVM capability check is enough. */
>>> @@ -59,6 +106,7 @@ void kvm__arch_set_cmdline(char *cmdline, bool
>>> video)
>>> void kvm__arch_reset(struct kvm *kvm)
>>> {
>>> + INIT_LIST_HEAD(&kvm->cfg.arch.nvmem_list);
>>> }
>>>
>>> void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64
>>> ram_size) @@ -238,3 +286,89 @@ int kvm__arch_setup_firmware(struct
>>> kvm *kvm) {
>>> return 0;
>>> }
>>> +
>>> +static int setup_nvmem(struct kvm *kvm)
>>> +{
>>> + u64 map_address = ARM_NVRAM_AREA;
>>> + const u64 limit = ARM_NVRAM_AREA + ARM_NVRAM_SIZE;
>>> + struct list_head *nvmem_node;
>>> + const int pagesize = getpagesize();
>>> +
>>> + list_for_each(nvmem_node, &kvm->cfg.arch.nvmem_list) {
>>> + struct kvm_nv_mem *nvmem = container_of(nvmem_node,
>>> + struct
>>> kvm_nv_mem,
>>> + node);
>>> + void *user_addr;
>>> + int fd;
>>> +
>>> + if (map_address + nvmem->size > limit)
>>> + die("cannot map file %s in non-volatile
>>> memory, no space left",
>>> + nvmem->data_file);
>>> +
>>> + if (nvmem->size & (pagesize - 1))
>>> + die("size of non-volatile memory files must
>>> be a multiple of system page size (= %d)",
>>> + pagesize);
>>> +
>>> + user_addr = mmap(NULL, nvmem->size, PROT_RW,
>>> MAP_ANON_NORESERVE, -1, 0);
>>> + if (user_addr == MAP_FAILED)
>>> + die("cannot create mapping for file %s",
>>> + nvmem->data_file);
>>> +
>>> + fd = open(nvmem->data_file, O_RDONLY);
>>> + if (fd < 0)
>>> + die("cannot read file %s", nvmem->data_file);
>>> + if (read_file(fd, user_addr, nvmem->size) < 0)
>>> + die("failed to map nv memory data %s",
>>> + nvmem->data_file);
>>> + close(fd);
>>> +
>>> + if (kvm__register_dev_mem(kvm, map_address,
>>> nvmem->size,
>>> + user_addr))
>>> + die("failed to register nv memory mapping
>>> for guest"); +
>>> + nvmem->map_addr = map_address;
>>> + map_address += nvmem->size;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +firmware_init(setup_nvmem);
>>> +
>>> +static int flush_nv_mem(struct kvm *kvm)
>>> +{
>>> + struct list_head *nvmem_node;
>>> + int err = 0;
>>> +
>>> + list_for_each(nvmem_node, &kvm->cfg.arch.nvmem_list) {
>>> + struct kvm_nv_mem *nvmem = container_of(nvmem_node,
>>> + struct
>>> kvm_nv_mem,
>>> + node);
>>> + void *host_pos;
>>> +
>>> + host_pos = guest_flat_to_host(kvm,
>>> + nvmem->map_addr);
>>> +
>>> + if (nvmem->write_back) {
>>> + int fd;
>>> +
>>> + fd = open(nvmem->data_file, O_WRONLY);
>>> + if (fd < 0) {
>>> + pr_err("failed to open firmware data
>>> file for writting");
>>> + err = -1;
>>> + continue;
>>> + }
>>> +
>>> + if (write_in_full(fd, host_pos, nvmem->size)
>>> < 0) {
>>> + pr_err("failed to flush firmware
>>> data to file");
>>> + err = -1;
>>> + }
>>> + close(fd);
>>> + }
>>> +
>>> + if (munmap(host_pos, nvmem->size))
>>> + err = -1;
>>> + }
>>> +
>>> + return err;
>>> +}
>>> +firmware_exit(flush_nv_mem);
>>
>
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