On Mon, Aug 10, 2020 at 3:40 PM Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx> wrote: > > According to section "Canonicalization and Consistency Checks" in APM vol. 2 > the following guest state combinations are illegal: > > * EFER.LME and CR0.PG are both set and CR4.PAE is zero. > * EFER.LME and CR0.PG are both non-zero and CR0.PE is zero. > * EFER.LME, CR0.PG, CR4.PAE, CS.L, and CS.D are all non-zero > > Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx> > --- > x86/svm_tests.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 44 insertions(+) > > diff --git a/x86/svm_tests.c b/x86/svm_tests.c > index 1908c7c..43208fd 100644 > --- a/x86/svm_tests.c > +++ b/x86/svm_tests.c > @@ -1962,7 +1962,51 @@ static void test_efer(void) > SVM_TEST_REG_RESERVED_BITS(16, 63, 4, "EFER", vmcb->save.efer, > efer_saved, SVM_EFER_RESERVED_MASK); > > + /* > + * EFER.LME and CR0.PG are both set and CR4.PAE is zero. > + */ > + u64 cr0_saved = vmcb->save.cr0; > + u64 cr0; > + u64 cr4_saved = vmcb->save.cr4; > + u64 cr4; > + > + efer = efer_saved | EFER_LME; > + vmcb->save.efer = efer; > + cr0 = cr0_saved | X86_CR0_PG; > + vmcb->save.cr0 = cr0; > + cr4 = cr4_saved & ~X86_CR4_PAE; > + vmcb->save.cr4 = cr4; > + report(svm_vmrun() == SVM_EXIT_ERR, "EFER.LME=1 (%lx), " > + "CR0.PG=1 (%lx) and CR4.PAE=0 (%lx)", efer, cr0, cr4); This seems adequate, but you have to assume that CR0.PE is set, or you could just be testing the second rule (below). > + /* > + * EFER.LME and CR0.PG are both set and CR0.PE is zero. > + */ > + vmcb->save.cr4 = cr4_saved; > + cr0 &= ~X86_CR0_PE; > + vmcb->save.cr0 = cr0; > + report(svm_vmrun() == SVM_EXIT_ERR, "EFER.LME=1 (%lx), " > + "CR0.PG=1 and CR0.PE=0 (%lx)", efer, cr0); This too, seems adequate, but you have to assume that CR4.PAE is set, or you could just be testing the first rule (above). > + /* > + * EFER.LME, CR0.PG, CR4.PAE, CS.L, and CS.D are all non-zero. > + */ > + u32 cs_attrib_saved = vmcb->save.cs.attrib; > + u32 cs_attrib; > + > + cr4 = cr4_saved | X86_CR4_PAE; Or'ing in X86_CR4_PAE seems superfluous, since you have to assume that cr4_saved already has the bit set for the above test to be worthwhile. > + vmcb->save.cr4 = cr4; > + cs_attrib = cs_attrib_saved | SVM_SELECTOR_L_MASK | > + SVM_SELECTOR_DB_MASK; > + vmcb->save.cs.attrib = cs_attrib; At this point, the second rule still applies (EFER.LME and CR0.PG are both set and CR0.PE is zero), so this doesn't necessarily verify the third rule at all. > + report(svm_vmrun() == SVM_EXIT_ERR, "EFER.LME=1 (%lx), " > + "CR0.PG=1 (%lx), CR4.PAE=1 (%lx), CS.L=1 and CS.D=1 (%x)", > + efer, cr0, cr4, cs_attrib); > + > + vmcb->save.cr4 = cr4_saved; > + vmcb->save.cs.attrib = cs_attrib_saved; > vmcb->save.efer = efer_saved; > + vmcb->save.cr0 = cr0_saved; > } > > static void test_cr0(void) > -- > 2.18.4 >
