Linux has started using RDTSCP as of v5.1. This has highlighted a bug in Xen,
where virtual vmexit simply gives up.
(XEN) d1v1 Unhandled nested vmexit: reason 51
(XEN) domain_crash called from vvmx.c:2671
(XEN) Domain 1 (vcpu#1) crashed on cpu#2:
Handle RDTSCP in the virtual vmexit hander in the same was as RDTSC
intercepts.
Reported-by: Sarah Newman <srn@prgmr.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Chris Brannon <cmb@prgmr.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wl@xen.org>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Jun Nakajima <jun.nakajima@intel.com>
CC: Kevin Tian <kevin.tian@intel.com>
CC: Juergen Gross <jgross@suse.com>
This probably wants backporting to all stable trees, even though nested virt
isn't supported, and therefore ought to qualify for 4.13 at this point.
---
xen/arch/x86/hvm/vmx/vvmx.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/xen/arch/x86/hvm/vmx/vvmx.c b/xen/arch/x86/hvm/vmx/vvmx.c
index fdf449bfd1..6696bd6240 100644
--- a/xen/arch/x86/hvm/vmx/vvmx.c
+++ b/xen/arch/x86/hvm/vmx/vvmx.c
@@ -2491,6 +2491,7 @@ int nvmx_n2_vmexit_handler(struct cpu_user_regs *regs,
nvcpu->nv_vmexit_pending = 1;
break;
case EXIT_REASON_RDTSC:
+ case EXIT_REASON_RDTSCP:
ctrl = __n2_exec_control(v);
if ( ctrl & CPU_BASED_RDTSC_EXITING )
nvcpu->nv_vmexit_pending = 1;
@@ -2501,6 +2502,8 @@ int nvmx_n2_vmexit_handler(struct cpu_user_regs *regs,
* avoiding changing guest_tsc and messing up timekeeping in L1
*/
msr_split(regs, hvm_get_guest_tsc(v) + get_vvmcs(v, TSC_OFFSET));
+ if ( exit_reason == EXIT_REASON_RDTSCP )
+ regs->rcx = v->arch.msrs->tsc_aux;
update_guest_eip();
return 1;
--
2.11.0
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On Thu, Oct 03, 2019 at 11:47:36AM +0100, Andrew Cooper wrote: > Linux has started using RDTSCP as of v5.1. This has highlighted a bug in Xen, > where virtual vmexit simply gives up. > > (XEN) d1v1 Unhandled nested vmexit: reason 51 > (XEN) domain_crash called from vvmx.c:2671 > (XEN) Domain 1 (vcpu#1) crashed on cpu#2: > > Handle RDTSCP in the virtual vmexit hander in the same was as RDTSC > intercepts. > > Reported-by: Sarah Newman <srn@prgmr.com> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > Tested-by: Chris Brannon <cmb@prgmr.com> Reviewed-by: Wei Liu <wl@xen.org> _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
On 03.10.19 12:47, Andrew Cooper wrote: > Linux has started using RDTSCP as of v5.1. This has highlighted a bug in Xen, > where virtual vmexit simply gives up. > > (XEN) d1v1 Unhandled nested vmexit: reason 51 > (XEN) domain_crash called from vvmx.c:2671 > (XEN) Domain 1 (vcpu#1) crashed on cpu#2: > > Handle RDTSCP in the virtual vmexit hander in the same was as RDTSC > intercepts. > > Reported-by: Sarah Newman <srn@prgmr.com> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > Tested-by: Chris Brannon <cmb@prgmr.com> Release-acked-by: Juergen Gross <jgross@suse.com> Juergen _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
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