On Mon, 16 May 2022 16:55:26 +0100
Alexandru Elisei <alexandru.elisei@xxxxxxx> wrote:
Hi,
> 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.
Just started to play with this, in general the series looks good to me on
a first glance. I will review in anger next week.
Meanwhile: when you start kvmtool without explicitly specifying a ram size
on the command line, the code misses to initialise cfg.ram_addr, so it
stays at 0 and kvmtool reports:
Fatal: RAM address is below 2GB
One possible fix would be to initialise this in get_ram_size() to
kvm__arch_default_ram_address(), I guess, but you might find a better solution.
Cheers,
Andre
>
> Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
> ---
> arm/aarch64/include/kvm/kvm-arch.h | 2 ++
> arm/aarch64/kvm.c | 5 ++++-
> arm/kvm.c | 7 +++++--
> builtin-run.c | 29 +++++++++++++++++++++++++----
> include/kvm/kvm-config.h | 1 +
> include/kvm/kvm.h | 12 ++++++++++++
> 6 files changed, 49 insertions(+), 7 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 af8e7eae0da2..14ffae9e39dc 100644
> --- a/arm/aarch64/kvm.c
> +++ b/arm/aarch64/kvm.c
> @@ -44,6 +44,9 @@ 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);
> }
>
> u64 kvm__arch_default_ram_address(void)
> @@ -117,7 +120,7 @@ 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 57c58be55159..26e6e9974009 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);
>
> @@ -147,15 +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, 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), \
> 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);
>
_______________________________________________
kvmarm mailing list
kvmarm@xxxxxxxxxxxxxxxxxxxxx
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
