From 0a8ef2fa450aa9673dd2e0d25bb16931aea2bf1e Mon Sep 17 00:00:00 2001 From: Rahul Singh Date: Wed, 7 Sep 2022 17:27:34 +0100 Subject: [PATCH] xen/evtchn: restrict the maximum number of evtchn supported for domUs Restrict the maximum number of evtchn supported for domUs to avoid allocating a large amount of memory in Xen. Set the default value of max_evtchn_port to 1023. The value of 1023 should be sufficient for guests because on ARM we don't bind physical interrupts to event channels. The only use of the evtchn port is inter-domain communications. Another reason why we choose the value of 1023 is to follow the default behavior of libxl. Signed-off-by: Rahul Singh Reviewed-by: Michal Orzel Acked-by: Julien Grall --- xen/arch/arm/domain_build.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c index 0277790088..f899766860 100644 --- a/xen/arch/arm/domain_build.c +++ b/xen/arch/arm/domain_build.c @@ -3277,7 +3277,13 @@ void __init create_domUs(void) struct xen_domctl_createdomain d_cfg = { .arch.gic_version = XEN_DOMCTL_CONFIG_GIC_NATIVE, .flags = XEN_DOMCTL_CDF_hvm | XEN_DOMCTL_CDF_hap, - .max_evtchn_port = -1, + /* + * The default of 1023 should be sufficient for guests because + * on ARM we don't bind physical interrupts to event channels. + * The only use of the evtchn port is inter-domain communications. + * 1023 is also the default value used in libxl. + */ + .max_evtchn_port = 1023, .max_grant_frames = -1, .max_maptrack_frames = -1, .grant_opts = XEN_DOMCTL_GRANT_version(opt_gnttab_max_version), -- 2.30.2