On init, the ccp device will make /sys/class/firmware/amd/loading etc firmware upload API attributes available to late-load a SEV-SNP firmware binary. The firmware upload api errors reported are actionable in the following ways: * FW_UPLOAD_ERR_HW_ERROR: the machine is in an unstable state and must be reset. * FW_UPLOAD_ERR_RW_ERROR: the firmware update went bad but can be recovered by hotloading the previous firmware version. Also used in the case that the kernel used the API wrong (bug). * FW_UPLOAD_ERR_FW_INVALID: user error with the data provided, but no instability is expected and no recovery actions are needed. * FW_UPLOAD_ERR_BUSY: upload attempted at a bad time either due to overload or the machine is in the wrong platform state. synthetic_restore_required: Instead of tracking the status of whether an individual GCTX is safe for use in a firmware command, force all following commands to fail with an error that is indicative of needing a firmware rollback. To test: 1. Build the kernel enabling SEV-SNP as normal and add CONFIG_FW_UPLOAD=y. 2. Add the following to your kernel_cmdline: ccp.psp_init_on_probe=0. 3.Get an AMD SEV-SNP firmware sbin appropriate to your Epyc chip model at https://www.amd.com/en/developer/sev.html and extract to get a .sbin file. 4. Run the following with your sbinfile in FW: echo 1 > /sys/class/firmware/snp_dlfw_ex/loading cat "${FW?}" > /sys/class/firmware/snp_dlfw_ex/data echo 0 > /sys/class/firmware/snp_dlfw_ex/loading 5. Verify the firmware update message in dmesg. Co-developed-by: Ashish Kalra <ashish.kalra@xxxxxxx> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx> Tested-by: Ashish Kalra <ashish.kalra@xxxxxxx> Signed-off-by: Dionna Glaze <dionnaglaze@xxxxxxxxxx> --- drivers/crypto/ccp/Kconfig | 2 + drivers/crypto/ccp/sev-dev.c | 12 +- drivers/crypto/ccp/sev-dev.h | 16 +++ drivers/crypto/ccp/sev-fw.c | 213 +++++++++++++++++++++++++++++++++++ 4 files changed, 241 insertions(+), 2 deletions(-) diff --git a/drivers/crypto/ccp/Kconfig b/drivers/crypto/ccp/Kconfig index f394e45e11ab4..520b1c84d11f4 100644 --- a/drivers/crypto/ccp/Kconfig +++ b/drivers/crypto/ccp/Kconfig @@ -39,6 +39,8 @@ config CRYPTO_DEV_SP_PSP bool "Platform Security Processor (PSP) device" default y depends on CRYPTO_DEV_CCP_DD && X86_64 && AMD_IOMMU + select FW_LOADER + select FW_UPLOAD help Provide support for the AMD Platform Security Processor (PSP). The PSP is a dedicated processor that provides support for key diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 32f7b6147905e..8c73f023b6420 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -485,7 +485,7 @@ void snp_free_firmware_page(void *addr) } EXPORT_SYMBOL_GPL(snp_free_firmware_page); -static void *sev_fw_alloc(unsigned long len) +void *sev_fw_alloc(unsigned long len) { struct page *page; @@ -853,6 +853,10 @@ static int __sev_do_cmd_locked(int cmd, void *data, int *psp_ret) if (WARN_ON_ONCE(!data != !buf_len)) return -EINVAL; + ret = sev_snp_synthetic_error(sev, psp_ret); + if (ret) + return ret; + /* * Copy the incoming data to driver's scratch buffer as __pa() will not * work for some memory, e.g. vmalloc'd addresses, and @data may not be @@ -1523,7 +1527,7 @@ void *psp_copy_user_blob(u64 uaddr, u32 len) } EXPORT_SYMBOL_GPL(psp_copy_user_blob); -static int sev_get_api_version(void) +int sev_get_api_version(void) { struct sev_device *sev = psp_master->sev_data; struct sev_user_data_status status; @@ -2320,6 +2324,8 @@ int sev_dev_init(struct psp_device *psp) if (ret) goto e_irq; + sev_snp_dev_init_firmware_upload(sev); + dev_notice(dev, "sev enabled\n"); return 0; @@ -2398,6 +2404,8 @@ void sev_dev_destroy(struct psp_device *psp) kref_put(&misc_dev->refcount, sev_exit); psp_clear_sev_irq_handler(psp); + + sev_snp_dev_init_firmware_upload(sev); } static int snp_shutdown_on_panic(struct notifier_block *nb, diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h index 28add34484ed1..52a423e7df84f 100644 --- a/drivers/crypto/ccp/sev-dev.h +++ b/drivers/crypto/ccp/sev-dev.h @@ -59,7 +59,13 @@ struct sev_device { bool snp_initialized; #ifdef CONFIG_FW_UPLOAD + /* Lock to protect fw_cancel */ + struct mutex fw_lock; + struct fw_upload *fwl; + bool fw_cancel; + u32 last_snp_asid; + bool synthetic_restore_required; u64 *snp_asid_to_gctx_pages_map; u64 *snp_unbound_gctx_pages; u32 snp_unbound_gctx_end; @@ -72,12 +78,22 @@ void sev_dev_destroy(struct psp_device *psp); void sev_pci_init(void); void sev_pci_exit(void); +void *sev_fw_alloc(unsigned long len); +int sev_get_api_version(void); +int sev_snp_download_firmware_ex(struct sev_device *sev, const u8 *data, u32 size, int *error); + #ifdef CONFIG_FW_UPLOAD void snp_cmd_bookkeeping_locked(int cmd, struct sev_device *sev, void *data); int sev_snp_platform_init_firmware_upload(struct sev_device *sev); +void sev_snp_dev_init_firmware_upload(struct sev_device *sev); +void sev_snp_destroy_firmware_upload(struct sev_device *sev); +int sev_snp_synthetic_error(struct sev_device *sev, int *psp_ret); #else static inline void snp_cmd_bookkeeping_locked(int cmd, struct sev_device *sev, void *data) { } static inline int sev_snp_platform_init_firmware_upload(struct sev_device *sev) { return 0; } +static inline void sev_snp_dev_init_firmware_upload(struct sev_device *sev) { } +static inline void sev_snp_destroy_firmware_upload(struct sev_device *sev) { } +static inline int sev_snp_synthetic_error(struct sev_device *sev, int *psp_ret) { return 0; } #endif /* CONFIG_FW_UPLOAD */ #endif /* __SEV_DEV_H */ diff --git a/drivers/crypto/ccp/sev-fw.c b/drivers/crypto/ccp/sev-fw.c index 55a5a572da8f1..97ce90f2af29a 100644 --- a/drivers/crypto/ccp/sev-fw.c +++ b/drivers/crypto/ccp/sev-fw.c @@ -4,6 +4,7 @@ */ #include <linux/firmware.h> +#include <linux/psp.h> #include <linux/psp-sev.h> #include <asm/sev.h> @@ -115,3 +116,215 @@ int sev_snp_platform_init_firmware_upload(struct sev_device *sev) } return 0; } + +static enum fw_upload_err snp_dlfw_ex_prepare(struct fw_upload *fw_upload, + const u8 *data, u32 size) +{ + return FW_UPLOAD_ERR_NONE; +} + +static enum fw_upload_err snp_dlfw_ex_poll_complete(struct fw_upload *fw_upload) +{ + return FW_UPLOAD_ERR_NONE; +} + +/* + * This may be called asynchronously with an on-going update. All other + * functions are called sequentially in a single thread. To avoid contention on + * register accesses, only update the cancel_request flag. Other functions will + * check this flag and handle the cancel request synchronously. + */ +static void snp_dlfw_ex_cancel(struct fw_upload *fw_upload) +{ + struct sev_device *sev = fw_upload->dd_handle; + + mutex_lock(&sev->fw_lock); + sev->fw_cancel = true; + mutex_unlock(&sev->fw_lock); +} + +static enum fw_upload_err snp_dlfw_ex_err_translate(struct sev_device *sev, int psp_ret) +{ + dev_dbg(sev->dev, "Failed to update SEV firmware: %#x\n", psp_ret); + /* + * Operation error: + * HW_ERROR: Critical error. Machine needs repairs now. + * RW_ERROR: Severe error. Roll back to the prior version to recover. + * User error: + * FW_INVALID: Bad input for this interface. + * BUSY: Wrong machine state to run download_firmware_ex. + */ + switch (psp_ret) { + case SEV_RET_RESTORE_REQUIRED: + dev_warn(sev->dev, "Firmware updated but unusable\n"); + dev_warn(sev->dev, "Need to do manual firmware rollback!!!\n"); + return FW_UPLOAD_ERR_RW_ERROR; + case SEV_RET_SHUTDOWN_REQUIRED: + /* No state changes made. Not a hardware error. */ + dev_warn(sev->dev, "Firmware image cannot be live updated\n"); + return FW_UPLOAD_ERR_FW_INVALID; + case SEV_RET_BAD_VERSION: + /* No state changes made. Not a hardware error. */ + dev_warn(sev->dev, "Firmware image is not well formed\n"); + return FW_UPLOAD_ERR_FW_INVALID; + /* SEV-specific errors that can still happen. */ + case SEV_RET_BAD_SIGNATURE: + /* No state changes made. Not a hardware error. */ + dev_warn(sev->dev, "Firmware image signature is bad\n"); + return FW_UPLOAD_ERR_FW_INVALID; + case SEV_RET_INVALID_PLATFORM_STATE: + /* Calling at the wrong time. Not a hardware error. */ + dev_warn(sev->dev, "Firmware not updated as SEV in INIT state\n"); + return FW_UPLOAD_ERR_BUSY; + case SEV_RET_HWSEV_RET_UNSAFE: + dev_err(sev->dev, "Firmware is unstable. Reset your machine!!!\n"); + return FW_UPLOAD_ERR_HW_ERROR; + /* Kernel bug cases. */ + case SEV_RET_INVALID_PARAM: + dev_err(sev->dev, "Download-firmware-EX invalid parameter\n"); + return FW_UPLOAD_ERR_RW_ERROR; + case SEV_RET_INVALID_ADDRESS: + dev_err(sev->dev, "Download-firmware-EX invalid address\n"); + return FW_UPLOAD_ERR_RW_ERROR; + default: + dev_err(sev->dev, "Unhandled download_firmware_ex err %d\n", psp_ret); + return FW_UPLOAD_ERR_HW_ERROR; + } +} + +static enum fw_upload_err snp_update_guest_statuses(struct sev_device *sev) +{ + struct sev_data_snp_guest_status status_data; + void *snp_guest_status; + enum fw_upload_err ret; + int error; + + /* + * Force an update of guest context pages after SEV firmware + * live update by issuing SNP_GUEST_STATUS on all guest + * context pages. + */ + snp_guest_status = sev_fw_alloc(PAGE_SIZE); + if (!snp_guest_status) + return FW_UPLOAD_ERR_INVALID_SIZE; + + /* + * After the last bound asid-to-gctx page is snp_unbound_gctx_end-many + * unbound gctx pages that also need updating. + */ + for (int i = 1; i <= sev->last_snp_asid + sev->snp_unbound_gctx_end; i++) { + if (sev->snp_asid_to_gctx_pages_map[i]) { + status_data.gctx_paddr = sev->snp_asid_to_gctx_pages_map[i]; + status_data.address = __psp_pa(snp_guest_status); + ret = sev_do_cmd(SEV_CMD_SNP_GUEST_STATUS, &status_data, &error); + if (ret) { + /* + * Handle race with SNP VM being destroyed/decommissoned, + * if guest context page invalid error is returned, + * assume guest has been destroyed. + */ + if (error == SEV_RET_INVALID_GUEST) + continue; + sev->synthetic_restore_required = true; + dev_err(sev->dev, "SNP GCTX update error: %#x\n", error); + dev_err(sev->dev, "Roll back SNP firmware!\n"); + snp_free_firmware_page(snp_guest_status); + ret = FW_UPLOAD_ERR_RW_ERROR; + goto fw_err; + } + } + } +fw_err: + snp_free_firmware_page(snp_guest_status); + return ret; +} + +static enum fw_upload_err snp_dlfw_ex_write(struct fw_upload *fwl, const u8 *data, + u32 offset, u32 size, u32 *written) +{ + struct sev_device *sev = fwl->dd_handle; + u8 api_major, api_minor, build; + int ret, error; + bool cancel; + + if (!sev) + return FW_UPLOAD_ERR_HW_ERROR; + + mutex_lock(&sev->fw_lock); + cancel = sev->fw_cancel; + mutex_unlock(&sev->fw_lock); + + if (cancel) + return FW_UPLOAD_ERR_CANCELED; + + /* + * SEV firmware update is a one-shot update operation, the write() + * callback to be invoked multiple times for the same update is + * unexpected. + */ + if (offset) + return FW_UPLOAD_ERR_INVALID_SIZE; + + if (sev_get_api_version()) + return FW_UPLOAD_ERR_HW_ERROR; + + api_major = sev->api_major; + api_minor = sev->api_minor; + build = sev->build; + + ret = sev_snp_download_firmware_ex(sev, data, size, &error); + if (ret) + return snp_dlfw_ex_err_translate(sev, error); + + ret = snp_update_guest_statuses(sev); + if (ret) + return ret; + + sev_get_api_version(); + if (api_major != sev->api_major || api_minor != sev->api_minor || + build != sev->build) { + dev_info(sev->dev, "SEV firmware updated from %d.%d.%d to %d.%d.%d\n", + api_major, api_minor, build, + sev->api_major, sev->api_minor, sev->build); + } else { + dev_info(sev->dev, "SEV firmware same as old %d.%d.%d\n", + api_major, api_minor, build); + } + + *written = size; + return FW_UPLOAD_ERR_NONE; +} + +static const struct fw_upload_ops snp_dlfw_ex_ops = { + .prepare = snp_dlfw_ex_prepare, + .write = snp_dlfw_ex_write, + .poll_complete = snp_dlfw_ex_poll_complete, + .cancel = snp_dlfw_ex_cancel, +}; + +void sev_snp_dev_init_firmware_upload(struct sev_device *sev) +{ + struct fw_upload *fwl; + + fwl = firmware_upload_register(THIS_MODULE, sev->dev, "snp_dlfw_ex", &snp_dlfw_ex_ops, sev); + + if (IS_ERR(fwl)) + dev_err(sev->dev, "SEV firmware upload initialization error %ld\n", PTR_ERR(fwl)); + + sev->fwl = fwl; + mutex_init(&sev->fw_lock); +} + +void sev_snp_destroy_firmware_upload(struct sev_device *sev) +{ + firmware_upload_unregister(sev->fwl); +} + +int sev_snp_synthetic_error(struct sev_device *sev, int *psp_ret) +{ + if (sev->synthetic_restore_required) { + *psp_ret = SEV_RET_RESTORE_REQUIRED; + return -EIO; + } + return 0; +} -- 2.47.0.199.ga7371fff76-goog
