From 91650010815f3da0834bc9781c4359350d1162a5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= Date: Tue, 27 Feb 2024 14:11:40 +0100 Subject: [PATCH 22/67] x86/spec: fix BRANCH_HARDEN option to only be set when build-enabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current logic to handle the BRANCH_HARDEN option will report it as enabled even when build-time disabled. Fix this by only allowing the option to be set when support for it is built into Xen. Fixes: 2d6f36daa086 ('x86/nospec: Introduce CONFIG_SPECULATIVE_HARDEN_BRANCH') Signed-off-by: Roger Pau Monné Reviewed-by: Jan Beulich master commit: 60e00f77a5cc671d30c5ef3318f5b8e9b74e4aa3 master date: 2024-02-26 16:06:42 +0100 --- xen/arch/x86/spec_ctrl.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c index 56e07d7536..661716d695 100644 --- a/xen/arch/x86/spec_ctrl.c +++ b/xen/arch/x86/spec_ctrl.c @@ -62,7 +62,8 @@ int8_t __initdata opt_psfd = -1; int8_t __ro_after_init opt_ibpb_ctxt_switch = -1; int8_t __read_mostly opt_eager_fpu = -1; int8_t __read_mostly opt_l1d_flush = -1; -static bool __initdata opt_branch_harden = true; +static bool __initdata opt_branch_harden = + IS_ENABLED(CONFIG_SPECULATIVE_HARDEN_BRANCH); bool __initdata bsp_delay_spec_ctrl; uint8_t __read_mostly default_xen_spec_ctrl; @@ -280,7 +281,16 @@ static int __init cf_check parse_spec_ctrl(const char *s) else if ( (val = parse_boolean("l1d-flush", s, ss)) >= 0 ) opt_l1d_flush = val; else if ( (val = parse_boolean("branch-harden", s, ss)) >= 0 ) - opt_branch_harden = val; + { + if ( IS_ENABLED(CONFIG_SPECULATIVE_HARDEN_BRANCH) ) + opt_branch_harden = val; + else + { + no_config_param("SPECULATIVE_HARDEN_BRANCH", "spec-ctrl", s, + ss); + rc = -EINVAL; + } + } else if ( (val = parse_boolean("srb-lock", s, ss)) >= 0 ) opt_srb_lock = val; else if ( (val = parse_boolean("unpriv-mmio", s, ss)) >= 0 ) -- 2.44.0