On 11/4/24 19:05, Dionna Glaze wrote:
> The DOWNLOAD_FIRMWARE_EX command requires cache flushing and introduces
> new error codes that could be returned to user space.
>
> The function is in sev-dev.c rather than sev-fw.c to avoid exposing the
> __sev_do_cmd_locked function in the sev-dev.h header.
Please say "why" this is being added.
>
> Signed-off-by: Dionna Glaze <dionnaglaze@xxxxxxxxxx>
> ---
> drivers/crypto/ccp/sev-dev.c | 66 +++++++++++++++++++++++++++++++-----
> include/linux/psp-sev.h | 26 ++++++++++++++
> include/uapi/linux/psp-sev.h | 5 +++
> 3 files changed, 89 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 9265b6d534bbe..32f7b6147905e 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -223,6 +223,7 @@ static int sev_cmd_buffer_len(int cmd)
> case SEV_CMD_SNP_GUEST_REQUEST: return sizeof(struct sev_data_snp_guest_request);
> case SEV_CMD_SNP_CONFIG: return sizeof(struct sev_user_data_snp_config);
> case SEV_CMD_SNP_COMMIT: return sizeof(struct sev_data_snp_commit);
> + case SEV_CMD_SNP_DOWNLOAD_FIRMWARE_EX: return sizeof(struct sev_data_download_firmware_ex);
> default: return 0;
> }
>
> @@ -1597,14 +1598,7 @@ static int sev_update_firmware(struct device *dev)
> return -1;
> }
>
> - /*
> - * SEV FW expects the physical address given to it to be 32
> - * byte aligned. Memory allocated has structure placed at the
> - * beginning followed by the firmware being passed to the SEV
> - * FW. Allocate enough memory for data structure + alignment
> - * padding + SEV FW.
> - */
> - data_size = ALIGN(sizeof(struct sev_data_download_firmware), 32);
> + data_size = ALIGN(sizeof(struct sev_data_download_firmware), SEV_FW_ALIGNMENT);
>
> order = get_order(firmware->size + data_size);
> p = alloc_pages(GFP_KERNEL, order);
> @@ -1645,6 +1639,62 @@ static int sev_update_firmware(struct device *dev)
> return ret;
> }
>
> +int sev_snp_download_firmware_ex(struct sev_device *sev, const u8 *data, u32 size, int *error)
> +{
> + struct sev_data_download_firmware_ex *data_ex;
> + int ret, order;
> + struct page *p;
> + u64 data_size;
> + void *fw_dest;
> +
> + data_size = ALIGN(sizeof(struct sev_data_download_firmware_ex),
> + SEV_FW_ALIGNMENT);
This can be a single line.
> +
> + order = get_order(size + data_size);
> + p = alloc_pages(GFP_KERNEL, order);
> + if (!p)
> + return -ENOMEM;
> +
> + /*
> + * Copy firmware data to a kernel allocated contiguous
> + * memory region.
> + */
> + data_ex = page_address(p);
> + fw_dest = page_address(p) + data_size;
> + memset(data_ex, 0, data_size);
> + memcpy(fw_dest, data, size);
> +
> + data_ex->address = __psp_pa(fw_dest);
> + data_ex->len = size;
> + data_ex->cmdlen = sizeof(struct sev_data_download_firmware_ex);
> +
> + /*
> + * SNP_COMMIT should be issued explicitly to commit the updated
> + * firmware after guest context pages have been updated.
> + */
> + ret = sev_do_cmd(SEV_CMD_SNP_DOWNLOAD_FIRMWARE_EX, data_ex, error);
> +
Remove blank line.
> + if (ret)
> + goto free_err;
> +
> + __free_pages(p, order);
If you remove this...
> +
> + /* Need to do a DF_FLUSH after live firmware update */
> + wbinvd_on_all_cpus();
> + ret = __sev_do_cmd_locked(SEV_CMD_SNP_DF_FLUSH, NULL, error);
> + if (ret) {
> + dev_dbg(sev->dev, "DF_FLUSH error %d\n", *error);
> + goto fw_err;
and remove this...
> + }
> +
> + return 0;
... you can remove this return 0 statement and the fw_err label.
> +
> +free_err:
> + __free_pages(p, order);
> +fw_err:
> + return ret;
> +}
> +
> static int __sev_snp_shutdown_locked(int *error, bool panic)
> {
> struct psp_device *psp = psp_master;
> diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
> index 903ddfea85850..6a08c56cd9771 100644
> --- a/include/linux/psp-sev.h
> +++ b/include/linux/psp-sev.h
> @@ -16,6 +16,15 @@
>
> #define SEV_FW_BLOB_MAX_SIZE 0x4000 /* 16KB */
>
> +/*
> + * SEV FW expects the physical address given to it to be 32
> + * byte aligned. Memory allocated has structure placed at the
> + * beginning followed by the firmware being passed to the SEV
> + * FW. Allocate enough memory for data structure + alignment
> + * padding + SEV FW.
> + */
> +#define SEV_FW_ALIGNMENT 32
Does this need to be in include/linux/psp-sev.h or can it go in
drivers/crypto/ccp/sev-dev.h ?
> +
> /**
> * SEV platform state
> */
> @@ -185,6 +194,23 @@ struct sev_data_download_firmware {
> u32 len; /* In */
> } __packed;
>
> +/**
> + * struct sev_data_download_firmware_ex - DOWNLOAD_FIRMWARE_EX command parameters
> + *
> + * @length: length of this command buffer
> + * @address: physical address of firmware image
> + * @len: len of the firmware image
> + * @commit: automatically commit the newly installed image
> + */
> +struct sev_data_download_firmware_ex {
> + u32 cmdlen; /* In */
This doesn't match the name above in the comment.
> + u32 reserved; /* In */
> + u64 address; /* In */
> + u32 len; /* In */
> + u32 commit:1; /* In */
> + u32 reserved2:31; /* In */
These names typically match what is in the spec, so I would expect to
see length, fw_paddr (or fw_address), and fw_len.
> +} __packed;
> +
> /**
> * struct sev_data_get_id - GET_ID command parameters
> *
> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
> index 832c15d9155bd..936464d4f282a 100644
> --- a/include/uapi/linux/psp-sev.h
> +++ b/include/uapi/linux/psp-sev.h
> @@ -80,6 +80,11 @@ typedef enum {
> SEV_RET_INVALID_PAGE_OWNER,
> SEV_RET_INVALID_PAGE_AEAD_OFLOW,
> SEV_RET_RMP_INIT_REQUIRED,
> + SEV_RET_BAD_SVN,
> + SEV_RET_BAD_VERSION,
> + SEV_RET_SHUTDOWN_REQUIRED,
> + SEV_RET_UPDATE_FAILED,
> + SEV_RET_RESTORE_REQUIRED,
Hmmm... yeah, as Alexey mentioned, these return values are not correct.
SEV_RET_INVALID_PAGE_SIZE should follow SEV_RET_SECURE_DATA_INVALID
so "SEV_RET_INVALID_KEY = 0x27" should be moved after
SEV_RET_RMP_INIT_REQUIRED
and SEV_RET_RMP_INIT_REQUIRED should be = 0x20, since RB_MODE_EXITED is
0x1f.
And then you might as well include RMP_INIT_FAILED in the list.
The list should look like:
...
SEV_RET_SECURE_DATA_INVALID,
SEV_RET_INVALID_PAGE_SIZE,
SEV_RET_INVALID_PAGE_STATE,
SEV_RET_INVALID_MDATA_ENTRY,
SEV_RET_INVALID_PAGE_OWNER,
SEV_RET_AEAD_OFLOW,
SEV_RET_RB_MODE_EXITED,
SEV_RET_RMP_INIT_REQUIRED,
SEV_RET_BAD_SVN,
SEV_RET_BAD_VERSION,
SEV_RET_SHUTDOWN_REQUIRED,
SEV_RET_UPDATE_FAILED,
SEV_RET_RESTORE_REQUIRED,
SEV_RET_RMP_INIT_FAILED,
SEV_RET_INVALID_KEY,
SEV_RET_MAX,
Of course this is already upstream in uapi, so I don't know how it is
supposed to be handled.
Thanks,
Tom
> SEV_RET_MAX,
> } sev_ret_code;
>
