On Thu, 2021-08-05 at 06:54 -0400, Paolo Bonzini wrote:
Accessing guest physical addresses at 0xFFFD_0000_0000 and above causes a failure on AMD processors because those addresses are reserved by HyperTransport (this is not documented). Avoid selftests failures by reserving those guest physical addresses.
Fixes: ef4c9f4f6546 ("KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn()") Cc: stable@vger.kernel.org Cc: David Matlack dmatlack@google.com Reported-by: Maxim Levitsky mlevitsk@redhat.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com
tools/testing/selftests/kvm/lib/kvm_util.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 10a8ed691c66..d995cc9836ee 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -309,6 +309,12 @@ struct kvm_vm *vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm) /* Limit physical addresses to PA-bits. */ vm->max_gfn = ((1ULL << vm->pa_bits) >> vm->page_shift) - 1; +#ifdef __x86_64__
- /* Avoid reserved HyperTransport region on AMD processors. */
- if (vm->pa_bits == 48)
vm->max_gfn = 0xfffcfffff;+#endif
- /* Allocate and setup memory for guest. */ vm->vpages_mapped = sparsebit_alloc(); if (phy_pages != 0)
I probably would have restricted this workaround to AMD vendor string, but I don't mind this to be like that as well at least for now.
Reviewed-by: Maxim Levitsky mlevitsk@redhat.com
Best regards, Maxim Levitsky