[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 1/2] x86/svm: Add SVME checking for SVM intercepts
On 12/21/2017 10:26 AM, Brian Woods wrote: > Checks the hvm EFER.SVME bit to make sure the EFER.SVME bit it high s/it/is > before allowing nested SVM intercepts to be handled successfully. On > SVME being low, it generates a #UD as per the AMD APM vol2 15.4. > > Reported-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> > Signed-off-by: Brian Woods <brian.woods@xxxxxxx> > --- > xen/arch/x86/hvm/svm/svm.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c > index 2e62b9bb6d..2d0a82ae77 100644 > --- a/xen/arch/x86/hvm/svm/svm.c > +++ b/xen/arch/x86/hvm/svm/svm.c > @@ -2587,6 +2587,35 @@ void svm_vmexit_handler(struct cpu_user_regs *regs) > eventinj.fields.vector) ) > vmcb->eventinj = eventinj; > > + /* > + * Making sure SVME is enabled see AMD APM vol2 section 15.4 > + * Nested Xen needs VMMCALL to boot. It hasn't set SVME by the time > + * it uses it, therefore it isn't checked > + */ > + switch ( exit_reason ) > + { > + case VMEXIT_VMRUN: > + case VMEXIT_VMLOAD: > + case VMEXIT_VMSAVE: > + case VMEXIT_CLGI: > + case VMEXIT_INVLPGA: > + if ( !(nestedhvm_enabled(v->domain) && > + nsvm_efer_svm_enabled(v)) ) I haven't checked all of them but at least for the first two (svm_vmexit_do_vmrun() and smv_vmexit_do_vmload()) we check EFER and print a similar error message. So it seems they can be handled in the switch statement below. -boris > + { > + gdprintk(XENLOG_ERR, "nestedhvm nested/SVME disabled, injecting > #UD\n"); > + hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC); > + goto out; > + } > + case VMEXIT_STGI: > + case VMEXIT_SKINIT: > + if ( !nestedhvm_enabled(v->domain) ) > + { > + gdprintk(XENLOG_ERR, "nestedhvm nested disabled, injecting > #UD\n"); > + hvm_inject_hw_exception(TRAP_invalid_op, X86_EVENT_NO_EC); > + goto out; > + } > + } > + > switch ( exit_reason ) > { > case VMEXIT_INTR: _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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