From: Hans-Jörg Höxer <hshoexer@genua.de>
Subject: Re: psp(4): Automatically load SEV firmware 3/3
To: <tech@openbsd.org>
Date: Mon, 28 Oct 2024 11:12:22 +0100

Hi,

thanks for the feedback!  Updated diff below.

Take care,
HJ.

----------------------------------------------------------------
commit b6b70ea473277f5ba04c3ba4a2c5995538785c92
Author: Hans-Joerg Hoexer <hshoexer@genua.de>
Date:   Tue Oct 1 18:49:01 2024 +0200

    psp(4): Automatically load SEV firmware
    
    When opening /dev/psp for the first time, load the SEV firmware.
    The firmware files will be provided as ports package.  The relevant
    firmware file is determined by CPU family and model (ci_family and
    ci_model).
    
    If no firmware files are installed or the right file could be
    determined, the PSP will be initialized using the on-chip firmware.

diff --git a/sys/dev/ic/psp.c b/sys/dev/ic/psp.c
index 92459c9e06f..d4c423dbd1c 100644
--- a/sys/dev/ic/psp.c
+++ b/sys/dev/ic/psp.c
@@ -21,6 +21,7 @@
 #include <sys/device.h>
 #include <sys/pledge.h>
 #include <sys/rwlock.h>
+#include <sys/malloc.h>
 
 #include <machine/bus.h>
 
@@ -58,6 +59,11 @@ struct psp_softc {
 
 	uint32_t		sc_flags;
 #define PSPF_INITIALIZED	0x1
+#define PSPF_UCODELOADED	0x2
+#define PSPF_NOUCODE		0x4
+
+	u_char			*sc_ucodebuf;
+	size_t			sc_ucodelen;
 };
 
 int	psp_get_pstatus(struct psp_softc *, struct psp_platform_status *);
@@ -65,6 +71,7 @@ int	psp_init(struct psp_softc *, struct psp_init *);
 int	psp_reinit(struct psp_softc *);
 int	psp_match(struct device *, void *, void *);
 void	psp_attach(struct device *, struct device *, void *);
+void	psp_load_ucode(struct psp_softc *);
 
 struct cfdriver psp_cd = {
 	NULL, "psp", DV_DULL
@@ -705,6 +712,8 @@ pspopen(dev_t dev, int flag, int mode, struct proc *p)
 	if (sc == NULL)
 		return (ENXIO);
 
+	psp_load_ucode(sc);
+
 	if (!(sc->sc_flags & PSPF_INITIALIZED))
 		return (psp_reinit(sc));
 
@@ -825,3 +834,68 @@ pspsubmatch(struct device *parent, void *match, void *aux)
 		return (0);
 	return ((*cf->cf_attach->ca_match)(parent, cf, aux));
 }
+
+struct ucode {
+	uint8_t		 family;
+	uint8_t	 	 model;
+	const char	*uname;
+} const psp_ucode_table[] = {
+	{ 0x17, 0x0, "amdsev/amd_sev_fam17h_model0xh.sbin" },
+	{ 0x17, 0x3, "amdsev/amd_sev_fam17h_model3xh.sbin" },
+	{ 0x19, 0x0, "amdsev/amd_sev_fam19h_model0xh.sbin" },
+	{ 0x19, 0x1, "amdsev/amd_sev_fam19h_model1xh.sbin" },
+	{ 0, 0, NULL }
+};
+
+void
+psp_load_ucode(struct psp_softc *sc)
+{
+	struct psp_downloadfirmware dlfw;
+	struct cpu_info		*ci = &cpu_info_primary;
+	const struct ucode	*uc;
+	uint8_t			 family, model;
+	int			 error;
+
+	if ((sc->sc_flags & PSPF_UCODELOADED) || (sc->sc_flags & PSPF_NOUCODE)
+	    || (sc->sc_flags & PSPF_INITIALIZED))
+		return;
+
+	family = ci->ci_family;
+	model = (ci->ci_model & 0xf0) >> 4;
+
+	for (uc = psp_ucode_table; uc->uname; uc++)
+		if ((uc->family == family) && (uc->model == model))
+			break;
+
+	if (uc->uname == NULL) {
+		printf("%s: no firmware found, CPU family 0x%x model 0x%x\n",
+		    sc->sc_dev.dv_xname, family, model);
+		sc->sc_flags |= PSPF_NOUCODE;
+		return;	/* no firmware found */
+	}
+
+	error = loadfirmware(uc->uname, &sc->sc_ucodebuf, &sc->sc_ucodelen);
+	if (error) {
+		if (error != ENOENT) {
+			printf("%s: error %d, could not read firmware %s\n",
+			    sc->sc_dev.dv_xname, error, uc->uname);
+		}
+		sc->sc_flags |= PSPF_NOUCODE;
+		return;
+	}
+
+	bzero(&dlfw, sizeof(dlfw));
+	dlfw.fw_len = sc->sc_ucodelen;
+	dlfw.fw_paddr = (uint64_t)sc->sc_ucodebuf;
+
+	if (psp_downloadfirmware(sc, &dlfw) < 0)
+		goto out;
+
+	sc->sc_flags |= PSPF_UCODELOADED;
+out:
+	if (sc->sc_ucodebuf) {
+		free(sc->sc_ucodebuf, M_DEVBUF, sc->sc_ucodelen);
+		sc->sc_ucodebuf = NULL;
+		sc->sc_ucodelen = 0;
+	}
+}