[kvmtool hack 2/3] kvmtool: arm64: Add support for guest physical address size

[Suzuki K Poulose]

Add an option to specify the physical address size used by this
VM.

Signed-off-by: Suzuki K Poulose <suzuki.poul...@arm.com>
---
 arm/aarch64/include/kvm/kvm-config-arch.h |  5 ++++-
 arm/include/arm-common/kvm-config-arch.h  |  1 +
 arm/kvm.c                                 | 30 ++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/arm/aarch64/include/kvm/kvm-config-arch.h 
b/arm/aarch64/include/kvm/kvm-config-arch.h
index 04be43d..c4bb207 100644
--- a/arm/aarch64/include/kvm/kvm-config-arch.h
+++ b/arm/aarch64/include/kvm/kvm-config-arch.h
@@ -8,7 +8,10 @@
                        "Create PMUv3 device"),                         \
        OPT_U64('\0', "kaslr-seed", &(cfg)->kaslr_seed,                 \
                        "Specify random seed for Kernel Address Space " \
-                       "Layout Randomization (KASLR)"),
+                       "Layout Randomization (KASLR)"),                \
+       OPT_UINTEGER('\0', "phys-shift", &(cfg)->phys_shift,            \
+                       "Specify maximum physical address size (not "   \
+                       "the amount of memory)"),
 
 #include "arm-common/kvm-config-arch.h"
 
diff --git a/arm/include/arm-common/kvm-config-arch.h 
b/arm/include/arm-common/kvm-config-arch.h
index 6a196f1..d841b0b 100644
--- a/arm/include/arm-common/kvm-config-arch.h
+++ b/arm/include/arm-common/kvm-config-arch.h
@@ -11,6 +11,7 @@ struct kvm_config_arch {
        bool            has_pmuv3;
        u64             kaslr_seed;
        enum irqchip_type irqchip;
+       unsigned int    phys_shift;
 };
 
 int irqchip_parser(const struct option *opt, const char *arg, int unset);
diff --git a/arm/kvm.c b/arm/kvm.c
index 2ab436e..7573391 100644
--- a/arm/kvm.c
+++ b/arm/kvm.c
@@ -18,6 +18,14 @@ struct kvm_ext kvm_req_ext[] = {
        { 0, 0 },
 };
 
+#ifndef KVM_CAP_ARM_CONFIG_PHYS_SHIFT
+#define KVM_CAP_ARM_CONFIG_PHYS_SHIFT  151
+#endif
+
+#ifndef KVM_ARM_SET_PHYS_SIZE
+#define KVM_ARM_SET_PHYS_SIZE          _IOW(KVMIO, 0xb2, __u32)
+#endif
+
 bool kvm__arch_cpu_supports_vm(void)
 {
        /* The KVM capability check is enough. */
@@ -57,8 +65,30 @@ void kvm__arch_set_cmdline(char *cmdline, bool video)
 {
 }
 
+static void kvm__init_phys_size(struct kvm *kvm)
+{
+       if (!kvm->cfg.arch.phys_shift)
+               goto default_phys_size;
+       if (kvm->cfg.arch.phys_shift > 48)
+               die("Physical memory size is limited to 48bits, %d\n",
+                       kvm->cfg.arch.phys_shift);
+
+       if (!kvm__supports_extension(kvm, KVM_CAP_ARM_CONFIG_PHYS_SHIFT)) {
+               pr_warning("System doesn't support phys size configuration\n");
+               goto default_phys_size;
+       }
+       if (ioctl(kvm->vm_fd, KVM_ARM_SET_PHYS_SIZE, &kvm->cfg.arch.phys_shift))
+               die("Failed to set physical memory size to %dbits\n",
+                       kvm->cfg.arch.phys_shift);
+       return;
+default_phys_size:
+       kvm->cfg.arch.phys_shift = 40;
+       return;
+}
+
 void kvm__arch_init(struct kvm *kvm, const char *hugetlbfs_path, u64 ram_size)
 {
+       kvm__init_phys_size(kvm);
        /*
         * Allocate guest memory. We must align our buffer to 64K to
         * correlate with the maximum guest page size for virtio-mmio.
-- 
2.13.6