On Mon, Nov 12, 2012 at 3:54 AM, Dong Aisheng [off-list ref] wrote:

On Sat, Nov 10, 2012 at 04:44:44PM +0100, Christoffer Dall wrote:

quoted

From: Marc Zyngier <redacted>

Wire the initial in-kernel MMIO support code for the VGIC, used
for the distributor emulation.

Signed-off-by: Marc Zyngier <redacted>
Signed-off-by: Christoffer Dall <redacted>
---
 arch/arm/include/asm/kvm_vgic.h |    6 +-
 arch/arm/kvm/Makefile           |    1
 arch/arm/kvm/vgic.c             |  138 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 144 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/kvm/vgic.c

diff --git a/arch/arm/include/asm/kvm_vgic.h b/arch/arm/include/asm/kvm_vgic.h
index d75540a..b444ecf 100644
--- a/arch/arm/include/asm/kvm_vgic.h
+++ b/arch/arm/include/asm/kvm_vgic.h

@@ -30,7 +30,11 @@ struct kvm_vcpu;
 struct kvm_run;
 struct kvm_exit_mmio;

-#ifndef CONFIG_KVM_ARM_VGIC
+#ifdef CONFIG_KVM_ARM_VGIC
+bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
+                   struct kvm_exit_mmio *mmio);
+
+#else
 static inline int kvm_vgic_hyp_init(void)
 {
      return 0;

diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
index 8a4f396..c019f02 100644
--- a/arch/arm/kvm/Makefile
+++ b/arch/arm/kvm/Makefile

@@ -20,3 +20,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += $(addprefix ../../../virt/kvm/, kvm_main.o coalesc

 obj-$(CONFIG_KVM_ARM_HOST) += arm.o guest.o mmu.o emulate.o reset.o
 obj-$(CONFIG_KVM_ARM_HOST) += coproc.o coproc_a15.o mmio.o decode.o
+obj-$(CONFIG_KVM_ARM_VGIC) += vgic.o

diff --git a/arch/arm/kvm/vgic.c b/arch/arm/kvm/vgic.c
new file mode 100644
index 0000000..26ada3b
--- /dev/null
+++ b/arch/arm/kvm/vgic.c

@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * 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, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <asm/kvm_emulate.h>
+
+#define ACCESS_READ_VALUE    (1 << 0)
+#define ACCESS_READ_RAZ              (0 << 0)
+#define ACCESS_READ_MASK(x)  ((x) & (1 << 0))
+#define ACCESS_WRITE_IGNORED (0 << 1)
+#define ACCESS_WRITE_SETBIT  (1 << 1)
+#define ACCESS_WRITE_CLEARBIT        (2 << 1)
+#define ACCESS_WRITE_VALUE   (3 << 1)
+#define ACCESS_WRITE_MASK(x) ((x) & (3 << 1))
+
+/**
+ * vgic_reg_access - access vgic register
+ * @mmio:   pointer to the data describing the mmio access
+ * @reg:    pointer to the virtual backing of the vgic distributor struct

Is this correct?

quoted

+ * @offset: least significant 2 bits used for word offset
+ * @mode:   ACCESS_ mode (see defines above)
+ *
+ * Helper to make vgic register access easier using one of the access
+ * modes defined for vgic register access
+ * (read,raz,write-ignored,setbit,clearbit,write)
+ */
+static void vgic_reg_access(struct kvm_exit_mmio *mmio, u32 *reg,
+                         u32 offset, int mode)
+{
+     int word_offset = offset & 3;
+     int shift = word_offset * 8;
+     u32 mask;
+     u32 regval;
+
+     /*
+      * Any alignment fault should have been delivered to the guest
+      * directly (ARM ARM B3.12.7 "Prioritization of aborts").
+      */
+
+     mask = (~0U) >> (word_offset * 8);
+     if (reg)
+             regval = *reg;
+     else {
+             BUG_ON(mode != (ACCESS_READ_RAZ | ACCESS_WRITE_IGNORED));
+             regval = 0;
+     }
+
+     if (mmio->is_write) {
+             u32 data = (*((u32 *)mmio->data) & mask) << shift;
+             switch (ACCESS_WRITE_MASK(mode)) {
+             case ACCESS_WRITE_IGNORED:
+                     return;
+
+             case ACCESS_WRITE_SETBIT:
+                     regval |= data;
+                     break;
+
+             case ACCESS_WRITE_CLEARBIT:
+                     regval &= ~data;
+                     break;
+
+             case ACCESS_WRITE_VALUE:
+                     regval = (regval & ~(mask << shift)) | data;
+                     break;
+             }
+             *reg = regval;
+     } else {
+             switch (ACCESS_READ_MASK(mode)) {
+             case ACCESS_READ_RAZ:
+                     regval = 0;
+                     /* fall through */
+
+             case ACCESS_READ_VALUE:
+                     *((u32 *)mmio->data) = (regval >> shift) & mask;
+             }
+     }
+}
+
+/* All this should be handled by kvm_bus_io_*()... FIXME!!! */
+struct mmio_range {
+     unsigned long base;
+     unsigned long len;
+     bool (*handle_mmio)(struct kvm_vcpu *vcpu, struct kvm_exit_mmio *mmio,
+                         u32 offset);
+};
+
+static const struct mmio_range vgic_ranges[] = {
+     {}
+};
+
+static const
+struct mmio_range *find_matching_range(const struct mmio_range *ranges,
+                                    struct kvm_exit_mmio *mmio,
+                                    unsigned long base)
+{
+     const struct mmio_range *r = ranges;
+     unsigned long addr = mmio->phys_addr - base;
+
+     while (r->len) {
+             if (addr >= r->base &&
+                 (addr + mmio->len) <= (r->base + r->len))
+                     return r;
+             r++;
+     }
+
+     return NULL;
+}
+
+/**
+ * vgic_handle_mmio - handle an in-kernel MMIO access
+ * @vcpu:    pointer to the vcpu performing the access
+ * @mmio:    pointer to the data describing the access

Can we also have @run here?

quoted

+ *
+ * returns true if the MMIO access has been performed in kernel space,
+ * and false if it needs to be emulated in user space.
+ */
+bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, struct kvm_exit_mmio *mmio)
+{
+     return KVM_EXIT_MMIO;
+}

thanks,
fixed

-Christoffer