[PATCH 2/8] kvm tools: Generate SPAPR PPC64 guest device tree

[Matt Evans <matt@ozlabs.org>]

The generated DT is the bare minimum structure required for SPAPR (on which
subsequent patches for VIO, XICS, PCI etc. will build); root node, cpus, memory.

Some aspects are currently hardwired for simplicity, for example advertised
page sizes, HPT size, SLB size, VMX/DFP, etc.  Future support of a variety
of POWER CPUs should acquire this info from the host and encode appropriately.

This requires a 64-bit libfdt.

Signed-off-by: Matt Evans <matt@ozlabs.org>
---
 tools/kvm/Makefile      |    3 +-
 tools/kvm/powerpc/kvm.c |  141 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 143 insertions(+), 1 deletions(-)

diff --git a/tools/kvm/Makefile b/tools/kvm/Makefile
index 58815a2..dc18959 100644
--- a/tools/kvm/Makefile
+++ b/tools/kvm/Makefile
@@ -129,7 +129,8 @@ ifeq ($(uname_M), ppc64)
 	OBJS	+= powerpc/kvm.o
 	OBJS	+= powerpc/kvm-cpu.o
 	ARCH_INCLUDE := powerpc/include
-	CFLAGS += -m64
+	CFLAGS 	+= -m64
+	LIBS 	+= -lfdt
 endif
 
 ###
diff --git a/tools/kvm/powerpc/kvm.c b/tools/kvm/powerpc/kvm.c
index 036bfc0..d792bee 100644
--- a/tools/kvm/powerpc/kvm.c
+++ b/tools/kvm/powerpc/kvm.c
@@ -3,6 +3,9 @@
  *
  * Copyright 2011 Matt Evans <matt@ozlabs.org>, IBM Corporation.
  *
+ * Portions of FDT setup borrowed from QEMU, copyright 2010 David Gibson, IBM
+ * Corporation.
+ *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published
  * by the Free Software Foundation.
@@ -28,8 +31,11 @@
 #include <asm/unistd.h>
 #include <errno.h>
 
+#include <linux/byteorder.h>
 #include <libfdt.h>
 
+#define HPT_ORDER 24
+
 #define HUGETLBFS_PATH "/var/lib/hugetlbfs/global/pagesize-16MB/"
 
 static char kern_cmdline[2048];
@@ -212,9 +218,144 @@ bool load_bzimage(struct kvm *kvm, int fd_kernel,
 	return false;
 }
 
+#define SMT_THREADS 4
+
+#define _FDT(exp)							\
+	do {								\
+		int ret = (exp);					\
+		if (ret < 0) {						\
+			die("Error creating device tree: %s: %s\n",	\
+			    #exp, fdt_strerror(ret));			\
+		}							\
+	} while (0)
+
+static uint32_t mfpvr(void)
+{
+	uint32_t r;
+	asm volatile ("mfpvr %0" : "=r"(r));
+	return r;
+}
+
 static void setup_fdt(struct kvm *kvm)
 {
+	uint64_t 	mem_reg_property[] = { 0, cpu_to_be64(kvm->ram_size) };
+	int 		smp_cpus = kvm->nrcpus;
+	uint32_t 	interrupt_server_ranges_prop[] = {0, cpu_to_be32(smp_cpus)};
+	char 		hypertas_prop_kvm[] = "hcall-pft\0hcall-term\0hcall-dabr\0hcall-interrupt"
+		"\0hcall-tce\0hcall-vio\0hcall-splpar\0hcall-bulk";
+	int 		i, j;
+	char 		cpu_name[30];
+	u8		staging_fdt[FDT_MAX_SIZE];
+	uint32_t      	pvr = mfpvr();
+
+	/* Generate an appropriate DT at kvm->fdt_gra */
+	void *fdt_dest = guest_flat_to_host(kvm, kvm->fdt_gra);
+	void *fdt = staging_fdt;
+
+	_FDT(fdt_create(fdt, FDT_MAX_SIZE));
+	_FDT(fdt_finish_reservemap(fdt));
+
+	_FDT(fdt_begin_node(fdt, ""));
+
+	_FDT(fdt_property_string(fdt, "device_type", "chrp"));
+	_FDT(fdt_property_string(fdt, "model", "IBM pSeries (emulated by kvmtool)"));
+	_FDT(fdt_property_cell(fdt, "#address-cells", 0x2));
+	_FDT(fdt_property_cell(fdt, "#size-cells", 0x2));
+
+	/* /chosen */
+	_FDT(fdt_begin_node(fdt, "chosen"));
+	/* cmdline */
+	_FDT(fdt_property_string(fdt, "bootargs", kern_cmdline));
+	/* Initrd */
+	if (kvm->initrd_size != 0) {
+		uint32_t ird_st_prop = cpu_to_be32(kvm->initrd_gra);
+		uint32_t ird_end_prop = cpu_to_be32(kvm->initrd_gra +
+						    kvm->initrd_size);
+		_FDT(fdt_property(fdt, "linux,initrd-start",
+				   &ird_st_prop, sizeof(ird_st_prop)));
+		_FDT(fdt_property(fdt, "linux,initrd-end",
+				   &ird_end_prop, sizeof(ird_end_prop)));
+	}
+
+	/* Memory: We don't alloc. a separate RMA yet.  If we ever need to
+	 * (CAP_PPC_RMA = 2) then have one memory node for 0->RMAsize, and
+	 * another RMAsize->endOfMem.
+	 */
+	_FDT(fdt_begin_node(fdt, "memory@0"));
+	_FDT(fdt_property_string(fdt, "device_type", "memory"));
+	_FDT(fdt_property(fdt, "reg", mem_reg_property, sizeof(mem_reg_property)));
+	_FDT(fdt_end_node(fdt));
+
+	/* CPUs */
+	_FDT(fdt_begin_node(fdt, "cpus"));
+	_FDT(fdt_property_cell(fdt, "#address-cells", 0x1));
+	_FDT(fdt_property_cell(fdt, "#size-cells", 0x0));
+
+	for (i = 0; i < smp_cpus; i += SMT_THREADS) {
+		/* These page and segment sizes are a basic minimum set.  Really,
+		 * we should be fancier and work out what the host supports then
+		 * encode this here.
+		 */
+		int32_t page_sizes_prop[] = {0xc, 0x0, 0x1, 0xc, 0x0,
+					     0x18, 0x100, 0x1, 0x18, 0x0};
+		int32_t seg_sizes_prop[] = {0x1c, 0x28, 0xffffffff, 0xffffffff};
+		int32_t pft_size_prop[] = { 0, HPT_ORDER };
+		uint32_t servers_prop[SMT_THREADS];
+		uint32_t gservers_prop[SMT_THREADS * 2];
+		int threads = (smp_cpus - i) >= SMT_THREADS ? SMT_THREADS :
+			smp_cpus - i;
+
+		sprintf(cpu_name, "PowerPC,POWER7@%d", i);
+		_FDT(fdt_begin_node(fdt, cpu_name));
+		_FDT(fdt_property_string(fdt, "name", "PowerPC,POWER7"));
+		_FDT(fdt_property_string(fdt, "device_type", "cpu"));
+
+		_FDT(fdt_property_cell(fdt, "reg", i));
+		_FDT(fdt_property_cell(fdt, "cpu-version", pvr));
+		_FDT(fdt_property_cell(fdt, "dcache-block-size", 0x00000080));
+		_FDT(fdt_property_cell(fdt, "icache-block-size", 0x00000080));
+		_FDT(fdt_property_cell(fdt, "timebase-frequency", 512000000));
+		_FDT(fdt_property_cell(fdt, "clock-frequency", 0xddbab200));
+
+		/* SLB size is hardwired as we currently assume POWERn */
+		_FDT(fdt_property_cell(fdt, "ibm,slb-size", 32));
+		/* HPT size is also hardwired; KVM currently fixes it at 16MB
+		 * but the moment that changes we'll need to read it out of the
+		 * kernel.
+		 */
+		_FDT(fdt_property(fdt, "ibm,pft-size", pft_size_prop, sizeof(pft_size_prop)));
+
+		_FDT(fdt_property_string(fdt, "status", "okay"));
+		_FDT(fdt_property(fdt, "64-bit", NULL, 0));
+		/* A server for each thread in this core */
+		for (j = 0; j < SMT_THREADS; j++) {
+			servers_prop[j] = cpu_to_be32(i+j);
+			/* Hack borrowed from QEMU, direct the group queues back to cpu 0 */
+			gservers_prop[j*2] = cpu_to_be32(i+j);
+			gservers_prop[j*2 + 1] = 0;
+		}
+		_FDT(fdt_property(fdt, "ibm,ppc-interrupt-server#s",
+				   servers_prop, threads * sizeof(uint32_t)));
+		_FDT(fdt_property(fdt, "ibm,ppc-interrupt-gserver#s",
+				   gservers_prop, threads * 2 * sizeof(uint32_t)));
+		_FDT(fdt_property(fdt, "ibm,segment-page-sizes",
+				   page_sizes_prop, sizeof(page_sizes_prop)));
+		_FDT(fdt_property(fdt, "ibm,processor-segment-sizes",
+				  seg_sizes_prop, sizeof(seg_sizes_prop)));
+		/* And VMX / DFP */
+		_FDT(fdt_property_cell(fdt, "ibm,vmx", 0x2));
+		_FDT(fdt_property_cell(fdt, "ibm,dfp", 0x1));
+		_FDT(fdt_end_node(fdt));
+	}
+	_FDT(fdt_end_node(fdt));
+
+	/* Finalise: */
+	_FDT(fdt_end_node(fdt)); /* Root node */
+	_FDT(fdt_finish(fdt));
 
+	_FDT(fdt_open_into(fdt, fdt_dest, FDT_MAX_SIZE));
+	_FDT(fdt_add_mem_rsv(fdt_dest, kvm->rtas_gra, kvm->rtas_size));
+	_FDT(fdt_pack(fdt_dest));
 }
 
 /**