KVM: ppc: PowerPC 440 KVM implementation

This functionality is definitely experimental, but is capable of running
unmodified PowerPC 440 Linux kernels as guests on a PowerPC 440 host. (Only
tested with 440EP "Bamboo" guests so far, but with appropriate userspace
support other SoC/board combinations should work.)

See Documentation/powerpc/kvm_440.txt for technical details.

[stephen: build fix]

Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 83 insertions, 0 deletions

diff --git a/arch/powerpc/kvm/booke_host.c b/arch/powerpc/kvm/booke_host.c
new file mode 100644
index 000000000000..b480341bc31e
--- /dev/null
+++ b/arch/powerpc/kvm/booke_host.c
@@ -0,0 +1,83 @@
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Copyright IBM Corp. 2008
+ *
+ * Authors: Hollis Blanchard <hollisb@us.ibm.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+#include <asm/kvm_ppc.h>
+
+unsigned long kvmppc_booke_handlers;
+
+static int kvmppc_booke_init(void)
+{
+	unsigned long ivor[16];
+	unsigned long max_ivor = 0;
+	int i;
+
+	/* We install our own exception handlers by hijacking IVPR. IVPR must
+	 * be 16-bit aligned, so we need a 64KB allocation. */
+	kvmppc_booke_handlers = __get_free_pages(GFP_KERNEL | __GFP_ZERO,
+	                                         VCPU_SIZE_ORDER);
+	if (!kvmppc_booke_handlers)
+		return -ENOMEM;
+
+	/* XXX make sure our handlers are smaller than Linux's */
+
+	/* Copy our interrupt handlers to match host IVORs. That way we don't
+	 * have to swap the IVORs on every guest/host transition. */
+	ivor[0] = mfspr(SPRN_IVOR0);
+	ivor[1] = mfspr(SPRN_IVOR1);
+	ivor[2] = mfspr(SPRN_IVOR2);
+	ivor[3] = mfspr(SPRN_IVOR3);
+	ivor[4] = mfspr(SPRN_IVOR4);
+	ivor[5] = mfspr(SPRN_IVOR5);
+	ivor[6] = mfspr(SPRN_IVOR6);
+	ivor[7] = mfspr(SPRN_IVOR7);
+	ivor[8] = mfspr(SPRN_IVOR8);
+	ivor[9] = mfspr(SPRN_IVOR9);
+	ivor[10] = mfspr(SPRN_IVOR10);
+	ivor[11] = mfspr(SPRN_IVOR11);
+	ivor[12] = mfspr(SPRN_IVOR12);
+	ivor[13] = mfspr(SPRN_IVOR13);
+	ivor[14] = mfspr(SPRN_IVOR14);
+	ivor[15] = mfspr(SPRN_IVOR15);
+
+	for (i = 0; i < 16; i++) {
+		if (ivor[i] > max_ivor)
+			max_ivor = ivor[i];
+
+		memcpy((void *)kvmppc_booke_handlers + ivor[i],
+		       kvmppc_handlers_start + i * kvmppc_handler_len,
+		       kvmppc_handler_len);
+	}
+	flush_icache_range(kvmppc_booke_handlers,
+	                   kvmppc_booke_handlers + max_ivor + kvmppc_handler_len);
+
+	return kvm_init(NULL, sizeof(struct kvm_vcpu), THIS_MODULE);
+}
+
+static void __exit kvmppc_booke_exit(void)
+{
+	free_pages(kvmppc_booke_handlers, VCPU_SIZE_ORDER);
+	kvm_exit();
+}
+
+module_init(kvmppc_booke_init)
+module_exit(kvmppc_booke_exit)