diff options
Diffstat (limited to 'system/xen/xsa/xsa320-4.13-3.patch')
-rw-r--r-- | system/xen/xsa/xsa320-4.13-3.patch | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/system/xen/xsa/xsa320-4.13-3.patch b/system/xen/xsa/xsa320-4.13-3.patch new file mode 100644 index 0000000000000..b52eeb338adad --- /dev/null +++ b/system/xen/xsa/xsa320-4.13-3.patch @@ -0,0 +1,36 @@ +From: Andrew Cooper <andrew.cooper3@citrix.com> +Subject: x86/spec-ctrl: Update docs with SRBDS workaround + +RDRAND/RDSEED can be hidden using cpuid= to mitigate SRBDS if microcode +isn't available. + +This is part of XSA-320 / CVE-2020-0543. + +Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> +Acked-by: Julien Grall <jgrall@amazon.com> + +diff --git a/docs/misc/xen-command-line.pandoc b/docs/misc/xen-command-line.pandoc +index c780312531..81e12d053c 100644 +--- a/docs/misc/xen-command-line.pandoc ++++ b/docs/misc/xen-command-line.pandoc +@@ -481,12 +481,18 @@ choice of `dom0-kernel` is deprecated and not supported by all Dom0 kernels. + This option allows for fine tuning of the facilities Xen will use, after + accounting for hardware capabilities as enumerated via CPUID. + ++Unless otherwise noted, options only have any effect in their negative form, ++to hide the named feature(s). Ignoring a feature using this mechanism will ++cause Xen not to use the feature, nor offer them as usable to guests. ++ + Currently accepted: + + The Speculation Control hardware features `srbds-ctrl`, `md-clear`, `ibrsb`, + `stibp`, `ibpb`, `l1d-flush` and `ssbd` are used by default if available and +-applicable. They can be ignored, e.g. `no-ibrsb`, at which point Xen won't +-use them itself, and won't offer them to guests. ++applicable. They can all be ignored. ++ ++`rdrand` and `rdseed` can be ignored, as a mitigation to XSA-320 / ++CVE-2020-0543. + + ### cpuid_mask_cpu + > `= fam_0f_rev_[cdefg] | fam_10_rev_[bc] | fam_11_rev_b` |