Hi, Thank you for having a look! Replies below.
On Wed, Jun 01, 2022 at 02:39:55PM +0100, Andre Przywara wrote: > On Wed, 25 May 2022 12:23:41 +0100 > Alexandru Elisei <[email protected]> wrote: > > Hi, > > > From: Suzuki K Poulose <[email protected]> > > > > 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 <[email protected]> > > Signed-off-by: Alexandru Elisei <[email protected]> > > --- > > 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? Yes. > > > > > __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; I think that change alone breaks the logic. The code needs to advance next if and only if it matches on one of the characters. I'll have a go at advancing next in each of the switch arms above (with the exception of the default one, which I'll add) to see how it ends up looking. > > > + } 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. This was intentional on my part, because I was under the impression that kvmtool treats all instances where errno != 0 as a fatal error. I think I was wrong about that, I see at least one instance when that isn't the case, in kvm_setup_guest_init -> extract_file. So it isn't a rule that a non-zero errno is a fatal error. I'll change the code to zero errno 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()? strtoull does not consider an error to convert the string "0" to an unsigned long long. Thanks, Alex > > Cheers, > Andre > > > + > > + 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", > _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
