Re: [PATCH v3 kvmtool 09/13] builtin_run: Allow standard size specifiers for memory
From: Andre Przywara <andre.przywara@arm.com>
Date: 2022-06-01 13:42:09
Also in:
kvmarm
On Wed, 25 May 2022 12:23:41 +0100 Alexandru Elisei [off-list ref] wrote: Hi,
quoted hunk ↗ jump to hunk
From: Suzuki K Poulose <suzuki.poulose@arm.com> Allow the user to use the standard B (bytes), K (kilobytes), M (megabytes), G (gigabytes), T (terabytes) and P (petabytes) suffixes for memory size. When none are specified, the default is megabytes. Also raise an error if the guest specifies 0 as the memory size, instead of treating it as uninitialized, as kvmtool has done so far. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Alexandru Elisei <redacted> --- builtin-run.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 60 insertions(+), 5 deletions(-)diff --git a/builtin-run.c b/builtin-run.c index 2ef159cdb2a3..a49698d5b2fe 100644 --- a/builtin-run.c +++ b/builtin-run.c@@ -49,9 +49,11 @@ #include <ctype.h> #include <stdio.h> -#define MB_SHIFT (20) #define KB_SHIFT (10) +#define MB_SHIFT (20) #define GB_SHIFT (30) +#define TB_SHIFT (40) +#define PB_SHIFT (50)
Can we lose the parentheses?
quoted hunk ↗ jump to hunk
__thread struct kvm_cpu *current_kvm_cpu;@@ -87,6 +89,60 @@ void kvm_run_set_wrapper_sandbox(void) kvm_run_wrapper = KVM_RUN_SANDBOX; } +static int parse_mem_unit(char **next) +{ + int shift = -1; + + switch (**next) { + case 'B': case 'b': shift = 0; break; + case 'K': case 'k': shift = KB_SHIFT; break; + case 'M': case 'm': shift = MB_SHIFT; break; + case 'G': case 'g': shift = GB_SHIFT; break; + case 'T': case 't': shift = TB_SHIFT; break; + case 'P': case 'p': shift = PB_SHIFT; break; + } + + if (shift == -1) { + /* The default is megabytes. */ + shift = MB_SHIFT;
Doesn't that look better inside the switch/case? default: return MB_SHIFT;
+ } else {
+ (*next)++;
+ }
+
+ return shift;
+}
+
+static u64 parse_mem_option(const char *nptr, char **next)
+{
+ u64 shift;
+ u64 val;
+
+ val = strtoull(nptr, next, 10);
+ if (errno == ERANGE)
+ die("Memory too large: %s", nptr);strtoull does not clear errno if it succeeds, so it retains the previous error value. So we would need to set errno to 0 just before calling strtoull.
+ shift = parse_mem_unit(next);
+
+ if ((val << shift) < val)
+ die("Memory too large: %s", nptr);
+
+ return val << shift;
+}
+
+static int mem_parser(const struct option *opt, const char *arg, int unset)
+{
+ struct kvm *kvm = opt->ptr;
+ char *next;
+
+ kvm->cfg.ram_size = parse_mem_option(arg, &next);
+ if (kvm->cfg.ram_size == 0)
+ die("Invalid RAM size: %s", arg);Does 0 hold any significant value (anymore)? I think we die() if we encounter invalid values in parse_mem_option()? Cheers, Andre
quoted hunk ↗ jump to hunk
+ + if (*next != '\0') + die("Invalid memory specifier: %s", arg); + + return 0; +} + #ifndef OPT_ARCH_RUN #define OPT_ARCH_RUN(...) #endif@@ -97,8 +153,9 @@ void kvm_run_set_wrapper_sandbox(void) OPT_STRING('\0', "name", &(cfg)->guest_name, "guest name", \ "A name for the guest"), \ OPT_INTEGER('c', "cpus", &(cfg)->nrcpus, "Number of CPUs"), \ - OPT_U64('m', "mem", &(cfg)->ram_size, "Virtual machine memory" \ - " size in MB."), \ + OPT_CALLBACK('m', "mem", NULL, "size[BKMGTP]", \ + "Virtual machine memory size, by default measured" \ + " in megabytes (M)", mem_parser, kvm), \ OPT_CALLBACK('d', "disk", kvm, "image or rootfs_dir", "Disk " \ " image or rootfs directory", img_name_parser, \ kvm), \@@ -522,8 +579,6 @@ static void kvm_run_validate_cfg(struct kvm *kvm) pr_warning("Ignoring initrd file when loading a firmware image"); if (kvm->cfg.ram_size) { - /* User specifies RAM size in megabytes. */ - kvm->cfg.ram_size <<= MB_SHIFT; available_ram = host_ram_size(); if (available_ram && kvm->cfg.ram_size > available_ram) { pr_warning("Guest memory size %lluMB exceeds host physical RAM size %lluMB",
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