Allow the user to specify the RAM base address by using -m/--mem size@addr
command line argument. The base address must be above 2GB, as to not
overlap with the MMIO I/O region.
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
---
arm/aarch64/include/kvm/kvm-arch.h | 2 ++
arm/aarch64/kvm.c | 14 ++++++++----
arm/kvm.c | 7 ++++--
builtin-run.c | 36 ++++++++++++++++++++++++++----
include/kvm/kvm-config.h | 1 +
include/kvm/kvm.h | 12 ++++++++++
include/linux/sizes.h | 2 ++
7 files changed, 64 insertions(+), 10 deletions(-)
diff --git a/arm/aarch64/include/kvm/kvm-arch.h b/arm/aarch64/include/kvm/kvm-arch.h
index ff857ca6e7b4..02d09a413831 100644
--- a/arm/aarch64/include/kvm/kvm-arch.h
+++ b/arm/aarch64/include/kvm/kvm-arch.h
@@ -10,6 +10,8 @@ void kvm__arch_enable_mte(struct kvm *kvm);
#define MAX_PAGE_SIZE SZ_64K
+#define ARCH_HAS_CFG_RAM_ADDRESS 1
+
#include "arm-common/kvm-arch.h"
#endif /* KVM__KVM_ARCH_H */
diff --git a/arm/aarch64/kvm.c b/arm/aarch64/kvm.c
index 357936844046..54200c9eec9d 100644
--- a/arm/aarch64/kvm.c
+++ b/arm/aarch64/kvm.c
@@ -4,6 +4,7 @@
#include <linux/byteorder.h>
#include <linux/cpumask.h>
+#include <linux/sizes.h>
#include <kvm/util.h>
@@ -39,10 +40,15 @@ int vcpu_affinity_parser(const struct option *opt, const char *arg, int unset)
void kvm__arch_validate_cfg(struct kvm *kvm)
{
+
+ if (kvm->cfg.ram_addr < ARM_MEMORY_AREA) {
+ die("RAM address is below the I/O region ending at %luGB",
+ ARM_MEMORY_AREA >> 30);
+ }
+
if (kvm->cfg.arch.aarch32_guest &&
- kvm->cfg.ram_size > ARM_LOMAP_MAX_MEMORY) {
- die("RAM size 0x%llx exceeds maximum allowed 0x%llx",
- kvm->cfg.ram_size, ARM_LOMAP_MAX_MEMORY);
+ kvm->cfg.ram_addr + kvm->cfg.ram_size > SZ_4G) {
+ die("RAM extends above 4GB");
}
}
@@ -117,7 +123,7 @@ int kvm__get_vm_type(struct kvm *kvm)
return 0;
/* Otherwise, compute the minimal required IPA size */
- max_ipa = ARM_MEMORY_AREA + kvm->cfg.ram_size - 1;
+ max_ipa = kvm->cfg.ram_addr + kvm->cfg.ram_size - 1;
ipa_bits = max(32, fls_long(max_ipa));
pr_debug("max_ipa %lx ipa_bits %d max_ipa_bits %d",
max_ipa, ipa_bits, max_ipa_bits);
diff --git a/arm/kvm.c b/arm/kvm.c
index abcccfabf59e..d51cc15d8b1c 100644
--- a/arm/kvm.c
+++ b/arm/kvm.c
@@ -55,7 +55,7 @@ void kvm__init_ram(struct kvm *kvm)
madvise(kvm->arch.ram_alloc_start, kvm->arch.ram_alloc_size,
MADV_HUGEPAGE);
- phys_start = ARM_MEMORY_AREA;
+ phys_start = kvm->cfg.ram_addr;
phys_size = kvm->ram_size;
host_mem = kvm->ram_start;
@@ -65,6 +65,9 @@ void kvm__init_ram(struct kvm *kvm)
"address 0x%llx [err %d]", phys_size, phys_start, err);
kvm->arch.memory_guest_start = phys_start;
+
+ pr_debug("RAM created at 0x%llx - 0x%llx",
+ phys_start, phys_start + phys_size - 1);
}
void kvm__arch_delete_ram(struct kvm *kvm)
@@ -201,7 +204,7 @@ bool kvm__load_firmware(struct kvm *kvm, const char *firmware_filename)
/* For default firmware address, lets load it at the begining of RAM */
if (fw_addr == 0)
- fw_addr = ARM_MEMORY_AREA;
+ fw_addr = kvm->arch.memory_guest_start;
if (!validate_fw_addr(kvm, fw_addr))
die("Bad firmware destination: 0x%016llx", fw_addr);
diff --git a/builtin-run.c b/builtin-run.c
index 8b4e865f0a0e..87023e390e73 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -125,12 +125,21 @@ static u64 parse_mem_option(const char *nptr, char **next)
static int mem_parser(const struct option *opt, const char *arg, int unset)
{
struct kvm *kvm = opt->ptr;
- char *next;
+ char *next, *nptr;
kvm->cfg.ram_size = parse_mem_option(arg, &next);
if (kvm->cfg.ram_size == 0)
die("Invalid RAM size: %s", arg);
+ if (kvm__arch_has_cfg_ram_address() && *next == '@') {
+ next++;
+ if (*next == '\0')
+ die("Missing memory address: %s", arg);
+
+ nptr = next;
+ kvm->cfg.ram_addr = parse_mem_option(nptr, &next);
+ }
+
if (*next != '\0')
die("Invalid memory specifier: %s", arg);
@@ -141,15 +150,26 @@ static int mem_parser(const struct option *opt, const char *arg, int unset)
#define OPT_ARCH_RUN(...)
#endif
+#ifdef ARCH_HAS_CFG_RAM_ADDRESS
+#define MEM_OPT_HELP_SHORT "size[BKMGTP][@addr[BKMGTP]]"
+#define MEM_OPT_HELP_LONG \
+ "Virtual machine memory size and optional base address, both" \
+ " measured by default in megabytes (M)"
+#else
+#define MEM_OPT_HELP_SHORT "size[BKMGTP]"
+#define MEM_OPT_HELP_LONG \
+ "Virtual machine memory size, by default measured in" \
+ " in megabytes (M)"
+#endif
+
#define BUILD_OPTIONS(name, cfg, kvm) \
struct option name[] = { \
OPT_GROUP("Basic options:"), \
OPT_STRING('\0', "name", &(cfg)->guest_name, "guest name", \
"A name for the guest"), \
OPT_INTEGER('c', "cpus", &(cfg)->nrcpus, "Number of CPUs"), \
- OPT_CALLBACK('m', "mem", NULL, "size[BKMGTP]", \
- "Virtual machine memory size, by default measured" \
- " in megabytes (M)", mem_parser, kvm), \
+ OPT_CALLBACK('m', "mem", NULL, MEM_OPT_HELP_SHORT, \
+ MEM_OPT_HELP_LONG, mem_parser, kvm), \
OPT_CALLBACK('d', "disk", kvm, "image or rootfs_dir", "Disk " \
" image or rootfs directory", img_name_parser, \
kvm), \
@@ -595,6 +615,14 @@ static struct kvm *kvm_cmd_run_init(int argc, const char **argv)
nr_online_cpus = sysconf(_SC_NPROCESSORS_ONLN);
kvm->cfg.custom_rootfs_name = "default";
+ /*
+ * An architecture can allow the user to set the RAM base address to
+ * zero. Initialize the address before parsing the command line
+ * arguments, otherwise it will be impossible to distinguish between the
+ * user setting the base address to zero or letting it unset and using
+ * the default value.
+ */
+ kvm->cfg.ram_addr = kvm__arch_default_ram_address();
while (argc != 0) {
BUILD_OPTIONS(options, &kvm->cfg, kvm);
diff --git a/include/kvm/kvm-config.h b/include/kvm/kvm-config.h
index 31bc89520d52..45fe1caaebce 100644
--- a/include/kvm/kvm-config.h
+++ b/include/kvm/kvm-config.h
@@ -23,6 +23,7 @@ struct kvm_config {
struct kvm_config_arch arch;
struct disk_image_params disk_image[MAX_DISK_IMAGES];
struct vfio_device_params *vfio_devices;
+ u64 ram_addr; /* Guest memory physical base address, in bytes */
u64 ram_size; /* Guest memory size, in bytes */
u8 num_net_devices;
u8 num_vfio_devices;
diff --git a/include/kvm/kvm.h b/include/kvm/kvm.h
index 360430b78b1e..eb23e2f77310 100644
--- a/include/kvm/kvm.h
+++ b/include/kvm/kvm.h
@@ -197,6 +197,18 @@ int kvm__arch_free_firmware(struct kvm *kvm);
bool kvm__arch_cpu_supports_vm(void);
void kvm__arch_read_term(struct kvm *kvm);
+#ifdef ARCH_HAS_CFG_RAM_ADDRESS
+static inline bool kvm__arch_has_cfg_ram_address(void)
+{
+ return true;
+}
+#else
+static inline bool kvm__arch_has_cfg_ram_address(void)
+{
+ return false;
+}
+#endif
+
void *guest_flat_to_host(struct kvm *kvm, u64 offset);
u64 host_to_guest_flat(struct kvm *kvm, void *ptr);
diff --git a/include/linux/sizes.h b/include/linux/sizes.h
index ce3e8150c174..bc621db852d9 100644
--- a/include/linux/sizes.h
+++ b/include/linux/sizes.h
@@ -44,4 +44,6 @@
#define SZ_1G 0x40000000
#define SZ_2G 0x80000000
+#define SZ_4G 0x100000000ULL
+
#endif /* __LINUX_SIZES_H__ */
--
2.36.1
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