rtas: Integrate RTAS blob

We implement RTAS as a simple binary blob which calls directly into QEMU
via a custom hcall. So far we were relying on QEMU putting the RTAS blob
to the guest memory with its location in linux,rtas-base/rtas-size.

The problems with this are:
1. we need to peek a location in the guest ram in addition to slof, FDT
and sometime kernel and init ram disk; having one less image makes QEMU's
life easier.
2. for secure VMs, it is yet another image which needs to be signed and
verified.

This implements "instantiate-rtas" completely in SLOF, including KVM PR
support ("broken sc1").

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

6 files changed, 49 insertions, 39 deletions

diff --git a/board-qemu/slof/rtas.fs b/board-qemu/slof/rtas.fs
index 092f5b1..90efe60 100644
--- a/board-qemu/slof/rtas.fs
+++ b/board-qemu/slof/rtas.fs
@@ -37,48 +37,13 @@ rtas-cb /rtas-control-block erase
 
 0 VALUE rtas-base
 0 VALUE rtas-size
-0 VALUE rtas-entry
 0 VALUE rtas-node
 
-\ Locate qemu RTAS, remove the linux,... properties we really don't
-\ want them to stick around
-
-372 cp
-
-: find-qemu-rtas ( -- )
-    " /rtas" find-device get-node to rtas-node
-
-    " linux,rtas-base" rtas-node get-package-property IF
-         device-end EXIT THEN
-    drop l@ to rtas-base
-    " linux,rtas-base" delete-property
-
-    " rtas-size" rtas-node get-package-property IF
-         device-end EXIT THEN
-    drop l@ to rtas-size
-
-    " linux,rtas-entry" rtas-node get-package-property IF
-        rtas-base to rtas-entry
-    ELSE
-        drop l@ to rtas-entry
-        " linux,rtas-entry" delete-property
-    THEN
-
-\    ." RTAS found, base=" rtas-base . ."  size=" rtas-size . cr
-
-    \ Patch the RTAS blob with our sc1 patcher if necessary
-    0
-    rtas-base
-    dup rtas-size +
-    check-and-patch-sc1
-
-    device-end
-;
-find-qemu-rtas
+s" /rtas" find-node to rtas-node
 373 cp
 
 : enter-rtas ( -- )
-    rtas-cb rtas-base 0 rtas-entry call-c drop
+    rtas-cb rtas-base 0 rtas-base call-c drop
 ;
 
 : rtas-get-token ( str len -- token | 0 )
@@ -185,9 +150,13 @@ rtas-node set-node
 : instantiate-rtas ( adr -- entry )
     dup store-rtas-loc
     dup rtas-base swap rtas-size move
-    rtas-entry rtas-base - +
 ;
 
+hv-rtas-get
+dup encode-int s" rtas-size" s" /rtas" find-node set-property
+to rtas-size
+to rtas-base
+
 device-end
 
 374 cp
diff --git a/lib/libhvcall/brokensc1.c b/lib/libhvcall/brokensc1.c
index d97ae77..f011570 100644
--- a/lib/libhvcall/brokensc1.c
+++ b/lib/libhvcall/brokensc1.c
@@ -36,7 +36,7 @@ static unsigned long hcall(uint32_t inst, unsigned long arg0, unsigned long arg1
 	return r3;
 }
 
-static int check_broken_sc1(void)
+int check_broken_sc1(void)
 {
 	long r;
 
diff --git a/lib/libhvcall/hvcall.S b/lib/libhvcall/hvcall.S
index 92cf22e..b19f6db 100644
--- a/lib/libhvcall/hvcall.S
+++ b/lib/libhvcall/hvcall.S
@@ -127,6 +127,27 @@ ENTRY(hv_cas)
 	HVCALL
 	blr
 
+/* This is the actual RTAS blob copied to the OS at instantiate-rtas */
+ENTRY(hv_rtas)
+	mr	r4,r3
+	lis	r3,KVMPPC_H_RTAS@h
+	ori	r3,r3,KVMPPC_H_RTAS@l
+	HVCALL
+	blr
+	.globl hv_rtas_size
+hv_rtas_size:
+	.long . - hv_rtas;
+
+ENTRY(hv_rtas_broken_sc1)
+	mr	r4,r3
+	lis	r3,KVMPPC_H_RTAS@h
+	ori	r3,r3,KVMPPC_H_RTAS@l
+	.long	0x7c000268
+	blr
+	.globl hv_rtas_broken_sc1_size
+hv_rtas_broken_sc1_size:
+	.long . - hv_rtas_broken_sc1;
+
 	.section ".bss"
 inbuf:	.space	16
 inlen:	.space	4
diff --git a/lib/libhvcall/hvcall.code b/lib/libhvcall/hvcall.code
index 5918c90..7e8536a 100644
--- a/lib/libhvcall/hvcall.code
+++ b/lib/libhvcall/hvcall.code
@@ -128,3 +128,17 @@ PRIM(hv_X2d_update_X2d_dt)
 	unsigned long dt = TOS.u;
 	TOS.u = hv_generic(KVMPPC_H_UPDATE_DT, dt);
 MIRP
+
+PRIM(hv_X2d_rtas_X2d_get)
+	if (check_broken_sc1()) {
+		PUSH;
+		TOS.u = (unsigned long) hv_rtas_broken_sc1;
+		PUSH;
+		TOS.u = hv_rtas_broken_sc1_size;
+	} else {
+		PUSH;
+		TOS.u = (unsigned long) hv_rtas;
+		PUSH;
+		TOS.u = hv_rtas_size;
+	}
+MIRP
diff --git a/lib/libhvcall/hvcall.in b/lib/libhvcall/hvcall.in
index 9193162..05ac386 100644
--- a/lib/libhvcall/hvcall.in
+++ b/lib/libhvcall/hvcall.in
@@ -18,6 +18,7 @@ cod(hv-free-crq)
 cod(hv-send-crq)
 cod(hv-put-tce)
 cod(check-and-patch-sc1)
+cod(hv-rtas-get)
 
 cod(RB@)
 cod(RB!)
diff --git a/lib/libhvcall/libhvcall.h b/lib/libhvcall/libhvcall.h
index caa4d6d..72c1f0f 100644
--- a/lib/libhvcall/libhvcall.h
+++ b/lib/libhvcall/libhvcall.h
@@ -97,11 +97,16 @@ extern unsigned long hv_logical_ci_store(unsigned long size, unsigned long addr,
 extern unsigned long hv_logical_memop(unsigned long dst, unsigned long src,
 				      unsigned long esize, unsigned long count,
 				      unsigned long op);
+extern int check_broken_sc1(void);
 extern int patch_broken_sc1(void *start, void *end, uint32_t *test_ins);
 
 extern unsigned long hv_cas(unsigned long vec, unsigned long buf,
 			unsigned long size);
 
+extern unsigned long hv_rtas(unsigned long params);
+extern unsigned long hv_rtas_broken_sc1(unsigned long params);
+extern unsigned int hv_rtas_size, hv_rtas_broken_sc1_size;
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __LIBHVCALL_H__ */