[PATCH v4 kvmtool 03/12] builtin-run: Rework RAM size validation
From: Alexandru Elisei <hidden>
Date: 2022-06-16 13:49:49
Also in:
kvmarm
Subsystem:
the rest · Maintainer:
Linus Torvalds
host_ram_size() uses sysconf() to calculate the available ram, and sysconf() can fail. When that happens, host_ram_size() returns 0. kvmtool warns the user when the configured VM ram size exceeds the size of the host's memory, but doesn't take into account that host_ram_size() can return 0. If the function returns zero, skip the warning. Since this can only happen when the user sets the memory size (via the -m/--mem command line argument), skip the check entirely if the user hasn't set it. Move the check to kvm_run_validate_cfg(), as it checks for valid user configuration. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Alexandru Elisei <redacted> --- builtin-run.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-)
diff --git a/builtin-run.c b/builtin-run.c
index 2bf93fe13c92..e1770b3c9df2 100644
--- a/builtin-run.c
+++ b/builtin-run.c@@ -509,6 +509,8 @@ static void kvm_run_set_real_cmdline(struct kvm *kvm) static void kvm_run_validate_cfg(struct kvm *kvm) { + u64 available_ram; + if (kvm->cfg.kernel_filename && kvm->cfg.firmware_filename) die("Only one of --kernel or --firmware can be specified");
@@ -518,6 +520,17 @@ static void kvm_run_validate_cfg(struct kvm *kvm) if (kvm->cfg.firmware_filename && kvm->cfg.initrd_filename) 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", + (unsigned long long)kvm->cfg.ram_size >> MB_SHIFT, + (unsigned long long)available_ram >> MB_SHIFT); + } + } } static struct kvm *kvm_cmd_run_init(int argc, const char **argv)
@@ -596,13 +609,6 @@ static struct kvm *kvm_cmd_run_init(int argc, const char **argv) if (!kvm->cfg.ram_size) kvm->cfg.ram_size = get_ram_size(kvm->cfg.nrcpus); - else - kvm->cfg.ram_size <<= MB_SHIFT; - - if (kvm->cfg.ram_size > host_ram_size()) - pr_warning("Guest memory size %lluMB exceeds host physical RAM size %lluMB", - (unsigned long long)kvm->cfg.ram_size >> MB_SHIFT, - (unsigned long long)host_ram_size() >> MB_SHIFT); if (!kvm->cfg.dev) kvm->cfg.dev = DEFAULT_KVM_DEV;
--
2.36.1
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