On Fri, May 10, 2024 at 10:03:46AM +0800, Tao Su wrote: >Use the max mappable GPA via GuestPhysBits advertised by KVM to calculate >max_gfn. Currently some selftests (e.g. access_tracking_perf_test, >dirty_log_test...) add RAM regions close to max_gfn, so guest may access >GPA beyond its mappable range and cause infinite loop. > >Adjust max_gfn in vm_compute_max_gfn() since x86 selftests already >overrides vm_compute_max_gfn() specifically to deal with goofy edge cases. > >Signed-off-by: Tao Su <tao1.su@xxxxxxxxxxxxxxx> >Tested-by: Yi Lai <yi1.lai@xxxxxxxxx> >--- >This patch is based on https://github.com/kvm-x86/linux/commit/b628cb523c65 > >Changelog: >v1 -> v2: > - Only adjust vm->max_gfn in vm_compute_max_gfn() > - Add Yi Lai's Tested-by > >v1: https://lore.kernel.org/all/20240508064205.15301-1-tao1.su@xxxxxxxxxxxxxxx/ >--- > tools/testing/selftests/kvm/include/x86_64/processor.h | 1 + > tools/testing/selftests/kvm/lib/x86_64/processor.c | 10 ++++++++-- > 2 files changed, 9 insertions(+), 2 deletions(-) > >diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h >index 81ce37ec407d..ff99f66d81a0 100644 >--- a/tools/testing/selftests/kvm/include/x86_64/processor.h >+++ b/tools/testing/selftests/kvm/include/x86_64/processor.h >@@ -282,6 +282,7 @@ struct kvm_x86_cpu_property { > #define X86_PROPERTY_MAX_EXT_LEAF KVM_X86_CPU_PROPERTY(0x80000000, 0, EAX, 0, 31) > #define X86_PROPERTY_MAX_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 0, 7) > #define X86_PROPERTY_MAX_VIRT_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 8, 15) >+#define X86_PROPERTY_MAX_GUEST_PHY_ADDR KVM_X86_CPU_PROPERTY(0x80000008, 0, EAX, 16, 23) > #define X86_PROPERTY_SEV_C_BIT KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 0, 5) > #define X86_PROPERTY_PHYS_ADDR_REDUCTION KVM_X86_CPU_PROPERTY(0x8000001F, 0, EBX, 6, 11) > >diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c >index 74a4c736c9ae..aa9966ead543 100644 >--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c >+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c >@@ -1293,10 +1293,16 @@ const struct kvm_cpuid2 *vcpu_get_supported_hv_cpuid(struct kvm_vcpu *vcpu) > unsigned long vm_compute_max_gfn(struct kvm_vm *vm) > { > const unsigned long num_ht_pages = 12 << (30 - vm->page_shift); /* 12 GiB */ >- unsigned long ht_gfn, max_gfn, max_pfn; >+ unsigned long ht_gfn, max_gfn, max_pfn, max_bits = 0; nit: max_bits has only 8 bits. so max_bits should be uint8_t. > uint8_t maxphyaddr; > >- max_gfn = (1ULL << (vm->pa_bits - vm->page_shift)) - 1; >+ if (kvm_cpu_has_p(X86_PROPERTY_MAX_GUEST_PHY_ADDR)) >+ max_bits = kvm_cpu_property(X86_PROPERTY_MAX_GUEST_PHY_ADDR); >+ >+ if (!max_bits) >+ max_bits = vm->pa_bits; >+ >+ max_gfn = (1ULL << (max_bits - vm->page_shift)) - 1; > > /* Avoid reserved HyperTransport region on AMD processors. */ > if (!host_cpu_is_amd) > >base-commit: 448b3fe5a0eab5b625a7e15c67c7972169e47ff8 >-- >2.34.1 >
