diff mbox series

[kvmtool,12/15] arm64: Allow the user to specify the RAM base address

Message ID 20220428155602.29445-13-alexandru.elisei@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Allow the user to set RAM base address | expand

Commit Message

Alexandru Elisei April 28, 2022, 3:55 p.m. UTC
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.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
---
 arm/aarch64/include/kvm/kvm-arch.h |  2 ++
 arm/aarch64/kvm.c                  |  5 ++++-
 arm/kvm.c                          |  7 +++++--
 builtin-run.c                      | 30 +++++++++++++++++++++++++-----
 include/kvm/kvm-config.h           |  1 +
 include/kvm/kvm.h                  | 12 ++++++++++++
 6 files changed, 49 insertions(+), 8 deletions(-)
diff mbox series

Patch

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 c52243b1f67f..581c836eb6ae 100644
--- a/arm/aarch64/kvm.c
+++ b/arm/aarch64/kvm.c
@@ -17,6 +17,9 @@  void kvm__arch_validate_cfg(struct kvm *kvm)
 		die("RAM size 0x%llx exceeds maximum allowed 0x%llx",
 		    kvm->cfg.ram_size, ARM_LOMAP_MAX_MEMORY);
 	}
+
+	if (kvm->cfg.ram_addr < ARM_MEMORY_AREA)
+		die("RAM address is below %luGB", ARM_MEMORY_AREA >> 30);
 }
 
 /*
@@ -85,7 +88,7 @@  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 0632a0c393a0..1eef1ffd0afc 100644
--- a/builtin-run.c
+++ b/builtin-run.c
@@ -131,12 +131,22 @@  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);
 
+	kvm->cfg.ram_addr = kvm__arch_default_ram_address();
+	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);
 
@@ -147,16 +157,26 @@  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."	\
+	" The default unit of measurement is megabytes (M)"
+#else
+#define MEM_OPT_HELP_SHORT	"size[BKMGTP]"
+#define MEM_OPT_HELP_LONG						\
+	"Virtual machine memory size."					\
+	" The default unit of measurement is 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. The default unit"	\
-		     " of measurement is 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),						\
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);