Re: [PATCH v2] x86/domain: revisit logging in arch_domain_create()

[Denis Mukhin <dmkhn@xxxxxxxxx>]

On Tuesday, April 1st, 2025 at 2:10 PM, dmkhn@xxxxxxxxx <dmkhn@xxxxxxxxx> wrote:

> 
> 
> From: Denis Mukhin dmukhin@xxxxxxxx
> 
> 
> Use %pd in all logs issued from arch_domain_create().
> 
> Also, expand error message in arch_domain_create() under
> !emulation_flags_ok() case to help debugging.
> 
> Signed-off-by: Denis Mukhin dmukhin@xxxxxxxx
> 
> ---
> Changes since v1:
> - dropped parentheses around "hardware" in the log message
> ---
> xen/arch/x86/domain.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
> 
> diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
> index 4989600627..bd887b4d44 100644
> --- a/xen/arch/x86/domain.c
> +++ b/xen/arch/x86/domain.c
> @@ -791,13 +791,12 @@ int arch_domain_create(struct domain *d,
> {
> if ( !opt_allow_unsafe )
> {
> - printk(XENLOG_G_ERR "Xen does not allow DomU creation on this CPU"
> - " for security reasons.\n");
> + printk(XENLOG_G_ERR "%pd: Xen does not allow DomU creation on this CPU"
> + " for security reasons.\n", d);

Forgot to remove full stops in the messages.
Sent v3:
  https://lore.kernel.org/xen-devel/20250402214406.115578-1-dmukhin@xxxxxxxx/

> return -EPERM;
> }
> printk(XENLOG_G_WARNING
> - "Dom%d may compromise security on this CPU.\n",
> - d->domain_id);
> 
> + "%pd: domain may compromise security on this CPU.\n", d);
> }
> 
> emflags = config->arch.emulation_flags;
> 
> @@ -807,16 +806,19 @@ int arch_domain_create(struct domain *d,
> 
> if ( emflags & ~XEN_X86_EMU_ALL )
> {
> - printk(XENLOG_G_ERR "d%d: Invalid emulation bitmap: %#x\n",
> - d->domain_id, emflags);
> 
> + printk(XENLOG_G_ERR "%pd: Invalid emulation bitmap: %#x\n",
> + d, emflags);
> return -EINVAL;
> }
> 
> if ( !emulation_flags_ok(d, emflags) )
> {
> - printk(XENLOG_G_ERR "d%d: Xen does not allow %s domain creation "
> + printk(XENLOG_G_ERR "%pd: Xen does not allow %s %sdomain creation "
> "with the current selection of emulators: %#x\n",
> - d->domain_id, is_hvm_domain(d) ? "HVM" : "PV", emflags);
> 
> + d,
> + is_hvm_domain(d) ? "HVM" : "PV",
> + is_hardware_domain(d) ? "hardware " : "",
> + emflags);
> return -EOPNOTSUPP;
> }
> d->arch.emulation_flags = emflags;
> 
> --
> 2.34.1