On 4/21/20 12:44 PM, Tom Lendacky wrote:
> To provide support for SEV-ES, the hypervisor must provide an area of
> memory to the PSP. Once this Trusted Memory Region (TMR) is provided to
> the PSP, the contents of this area of memory are no longer available to
> the x86.
>
> Update the PSP driver to allocate a 1MB region for the TMR that is 1MB
> aligned and then provide it to the PSP through the SEV INIT command.
>
> Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
>
> ---
Reviewed-by: Brijesh Singh <brijesh.singh@xxxxxxx>
> Changes since v1:
> - No need to over-allocate the memory area to obtain the required
> alignment when using the page allocator.
> ---
> drivers/crypto/ccp/sev-dev.c | 43 ++++++++++++++++++++++++++++++++++++
> include/linux/psp-sev.h | 2 ++
> include/uapi/linux/psp-sev.h | 2 ++
> 3 files changed, 47 insertions(+)
>
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 896f190b9a50..439cd737076e 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -20,6 +20,7 @@
> #include <linux/hw_random.h>
> #include <linux/ccp.h>
> #include <linux/firmware.h>
> +#include <linux/gfp.h>
>
> #include <asm/smp.h>
>
> @@ -44,6 +45,14 @@ MODULE_PARM_DESC(psp_probe_timeout, " default timeout value, in seconds, during
> static bool psp_dead;
> static int psp_timeout;
>
> +/* Trusted Memory Region (TMR):
> + * The TMR is a 1MB area that must be 1MB aligned. Use the page allocator
> + * to allocate the memory, which will return aligned memory for the specified
> + * allocation order.
> + */
> +#define SEV_ES_TMR_SIZE (1024 * 1024)
> +static void *sev_es_tmr;
> +
> static inline bool sev_version_greater_or_equal(u8 maj, u8 min)
> {
> struct sev_device *sev = psp_master->sev_data;
> @@ -214,6 +223,20 @@ static int __sev_platform_init_locked(int *error)
> if (sev->state == SEV_STATE_INIT)
> return 0;
>
> + if (sev_es_tmr) {
> + u64 tmr_pa;
> +
> + /*
> + * Do not include the encryption mask on the physical
> + * address of the TMR (firmware should clear it anyway).
> + */
> + tmr_pa = __pa(sev_es_tmr);
> +
> + sev->init_cmd_buf.flags |= SEV_INIT_FLAGS_SEV_ES;
> + sev->init_cmd_buf.tmr_address = tmr_pa;
> + sev->init_cmd_buf.tmr_len = SEV_ES_TMR_SIZE;
> + }
> +
> rc = __sev_do_cmd_locked(SEV_CMD_INIT, &sev->init_cmd_buf, error);
> if (rc)
> return rc;
> @@ -1012,6 +1035,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
> void sev_pci_init(void)
> {
> struct sev_device *sev = psp_master->sev_data;
> + struct page *tmr_page;
> int error, rc;
>
> if (!sev)
> @@ -1041,6 +1065,16 @@ void sev_pci_init(void)
> sev_update_firmware(sev->dev) == 0)
> sev_get_api_version();
>
> + /* Obtain the TMR memory area for SEV-ES use */
> + tmr_page = alloc_pages(GFP_KERNEL, get_order(SEV_ES_TMR_SIZE));
> + if (tmr_page) {
> + sev_es_tmr = page_address(tmr_page);
> + } else {
> + sev_es_tmr = NULL;
> + dev_warn(sev->dev,
> + "SEV: TMR allocation failed, SEV-ES support unavailable\n");
> + }
> +
> /* Initialize the platform */
> rc = sev_platform_init(&error);
> if (rc && (error == SEV_RET_SECURE_DATA_INVALID)) {
> @@ -1075,4 +1109,13 @@ void sev_pci_exit(void)
> return;
>
> sev_platform_shutdown(NULL);
> +
> + if (sev_es_tmr) {
> + /* The TMR area was encrypted, flush it from the cache */
> + wbinvd_on_all_cpus();
> +
> + free_pages((unsigned long)sev_es_tmr,
> + get_order(SEV_ES_TMR_SIZE));
> + sev_es_tmr = NULL;
> + }
> }
> diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
> index 5167bf2bfc75..7fbc8679145c 100644
> --- a/include/linux/psp-sev.h
> +++ b/include/linux/psp-sev.h
> @@ -100,6 +100,8 @@ struct sev_data_init {
> u32 tmr_len; /* In */
> } __packed;
>
> +#define SEV_INIT_FLAGS_SEV_ES 0x01
> +
> /**
> * struct sev_data_pek_csr - PEK_CSR command parameters
> *
> diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
> index 0549a5c622bf..91b4c63d5cbf 100644
> --- a/include/uapi/linux/psp-sev.h
> +++ b/include/uapi/linux/psp-sev.h
> @@ -83,6 +83,8 @@ struct sev_user_data_status {
> __u32 guest_count; /* Out */
> } __packed;
>
> +#define SEV_STATUS_FLAGS_CONFIG_ES 0x0100
> +
> /**
> * struct sev_user_data_pek_csr - PEK_CSR command parameters
> *
