diff options
Diffstat (limited to '0041-x86-spec-ctrl-Add-fine-grained-cmdline-suboptions-fo.patch')
| -rw-r--r-- | 0041-x86-spec-ctrl-Add-fine-grained-cmdline-suboptions-fo.patch | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/0041-x86-spec-ctrl-Add-fine-grained-cmdline-suboptions-fo.patch b/0041-x86-spec-ctrl-Add-fine-grained-cmdline-suboptions-fo.patch new file mode 100644 index 0000000..9964bb9 --- /dev/null +++ b/0041-x86-spec-ctrl-Add-fine-grained-cmdline-suboptions-fo.patch @@ -0,0 +1,137 @@ +From f066c8bb3e5686141cef6fa1dc86ea9f37c5388a Mon Sep 17 00:00:00 2001 +From: Andrew Cooper <andrew.cooper3@citrix.com> +Date: Tue, 12 Jul 2022 11:15:37 +0200 +Subject: [PATCH 41/51] x86/spec-ctrl: Add fine-grained cmdline suboptions for + primitives + +Support controling the PV/HVM suboption of msr-sc/rsb/md-clear, which +previously wasn't possible. + +Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> +Reviewed-by: Jan Beulich <jbeulich@suse.com> +master commit: 27357c394ba6e1571a89105b840ce1c6f026485c +master date: 2022-07-11 15:21:35 +0100 +--- + docs/misc/xen-command-line.pandoc | 12 ++++-- + xen/arch/x86/spec_ctrl.c | 66 ++++++++++++++++++++++++++----- + 2 files changed, 66 insertions(+), 12 deletions(-) + +diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc +index 46e9c58d35cd..1bbdb55129cc 100644 +--- a/docs/misc/xen-command-line.pandoc ++++ b/docs/misc/xen-command-line.pandoc +@@ -2233,7 +2233,8 @@ not be able to control the state of the mitigation. + By default SSBD will be mitigated at runtime (i.e `ssbd=runtime`). + + ### spec-ctrl (x86) +-> `= List of [ <bool>, xen=<bool>, {pv,hvm,msr-sc,rsb,md-clear}=<bool>, ++> `= List of [ <bool>, xen=<bool>, {pv,hvm}=<bool>, ++> {msr-sc,rsb,md-clear}=<bool>|{pv,hvm}=<bool>, + > bti-thunk=retpoline|lfence|jmp, {ibrs,ibpb,ssbd,psfd, + > eager-fpu,l1d-flush,branch-harden,srb-lock, + > unpriv-mmio}=<bool> ]` +@@ -2258,12 +2259,17 @@ in place for guests to use. + + Use of a positive boolean value for either of these options is invalid. + +-The booleans `pv=`, `hvm=`, `msr-sc=`, `rsb=` and `md-clear=` offer fine ++The `pv=`, `hvm=`, `msr-sc=`, `rsb=` and `md-clear=` options offer fine + grained control over the primitives by Xen. These impact Xen's ability to +-protect itself, and Xen's ability to virtualise support for guests to use. ++protect itself, and/or Xen's ability to virtualise support for guests to use. + + * `pv=` and `hvm=` offer control over all suboptions for PV and HVM guests + respectively. ++* Each other option can be used either as a plain boolean ++ (e.g. `spec-ctrl=rsb` to control both the PV and HVM sub-options), or with ++ `pv=` or `hvm=` subsuboptions (e.g. `spec-ctrl=rsb=no-hvm` to disable HVM ++ RSB only). ++ + * `msr-sc=` offers control over Xen's support for manipulating `MSR_SPEC_CTRL` + on entry and exit. These blocks are necessary to virtualise support for + guests and if disabled, guests will be unable to use IBRS/STIBP/SSBD/etc. +diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c +index ae74943c1053..9507e5da60a9 100644 +--- a/xen/arch/x86/spec_ctrl.c ++++ b/xen/arch/x86/spec_ctrl.c +@@ -147,20 +147,68 @@ static int __init parse_spec_ctrl(const char *s) + opt_rsb_hvm = val; + opt_md_clear_hvm = val; + } +- else if ( (val = parse_boolean("msr-sc", s, ss)) >= 0 ) ++ else if ( (val = parse_boolean("msr-sc", s, ss)) != -1 ) + { +- opt_msr_sc_pv = val; +- opt_msr_sc_hvm = val; ++ switch ( val ) ++ { ++ case 0: ++ case 1: ++ opt_msr_sc_pv = opt_msr_sc_hvm = val; ++ break; ++ ++ case -2: ++ s += strlen("msr-sc="); ++ if ( (val = parse_boolean("pv", s, ss)) >= 0 ) ++ opt_msr_sc_pv = val; ++ else if ( (val = parse_boolean("hvm", s, ss)) >= 0 ) ++ opt_msr_sc_hvm = val; ++ else ++ default: ++ rc = -EINVAL; ++ break; ++ } + } +- else if ( (val = parse_boolean("rsb", s, ss)) >= 0 ) ++ else if ( (val = parse_boolean("rsb", s, ss)) != -1 ) + { +- opt_rsb_pv = val; +- opt_rsb_hvm = val; ++ switch ( val ) ++ { ++ case 0: ++ case 1: ++ opt_rsb_pv = opt_rsb_hvm = val; ++ break; ++ ++ case -2: ++ s += strlen("rsb="); ++ if ( (val = parse_boolean("pv", s, ss)) >= 0 ) ++ opt_rsb_pv = val; ++ else if ( (val = parse_boolean("hvm", s, ss)) >= 0 ) ++ opt_rsb_hvm = val; ++ else ++ default: ++ rc = -EINVAL; ++ break; ++ } + } +- else if ( (val = parse_boolean("md-clear", s, ss)) >= 0 ) ++ else if ( (val = parse_boolean("md-clear", s, ss)) != -1 ) + { +- opt_md_clear_pv = val; +- opt_md_clear_hvm = val; ++ switch ( val ) ++ { ++ case 0: ++ case 1: ++ opt_md_clear_pv = opt_md_clear_hvm = val; ++ break; ++ ++ case -2: ++ s += strlen("md-clear="); ++ if ( (val = parse_boolean("pv", s, ss)) >= 0 ) ++ opt_md_clear_pv = val; ++ else if ( (val = parse_boolean("hvm", s, ss)) >= 0 ) ++ opt_md_clear_hvm = val; ++ else ++ default: ++ rc = -EINVAL; ++ break; ++ } + } + + /* Xen's speculative sidechannel mitigation settings. */ +-- +2.35.1 + |