Currently kvm_s2_fault_pin_pfn() handles a poisoned page directly by sending a SIGBUS signal itself.
This is an odd place to do it, the caller should decide what to do with errors, so move the handling to the sole caller, user_mem_abort(). This lays the foundation for stage 2 pre-faulting which, arising from a synthetic fault, should not send a signal. In order to do so, check to see if user_mem_abort()'s caller has set result - i.e. whether it wants to be informed about the outcome of the fault handling. If it does, then it is implied that it should handle the -EHWPOISON error itself. This is the case for pre-faulting. Otherwise this is real hardware, so send the signal. No functional change intended. Signed-off-by: Lorenzo Stoakes (ARM) <[email protected]> --- arch/arm64/kvm/mmu.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 8c23fef4ecf8..eae085a622ff 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1946,10 +1946,8 @@ static int kvm_s2_fault_pin_pfn(const struct kvm_s2_fault_desc *s2fd, kvm_s2_fault_is_write(s2fd) ? FOLL_WRITE : 0, &s2vi->map_writable, &s2vi->page); if (unlikely(is_error_noslot_pfn(s2vi->pfn))) { - if (s2vi->pfn == KVM_PFN_ERR_HWPOISON) { - kvm_send_hwpoison_signal(s2fd->hva, __ffs(s2vi->vma_pagesize)); - return 0; - } + if (s2vi->pfn == KVM_PFN_ERR_HWPOISON) + return -EHWPOISON; return -EFAULT; } @@ -2169,6 +2167,13 @@ static int user_mem_abort(const struct kvm_s2_fault_desc *s2fd, * get block mapping for device MMIO region. */ ret = kvm_s2_fault_pin_pfn(s2fd, &s2vi); + if (ret == -EHWPOISON) { + /* If result is specified, let the caller handle this. */ + if (result) + return -EHWPOISON; + kvm_send_hwpoison_signal(s2fd->hva, __ffs(s2vi.vma_pagesize)); + return 0; + } if (ret != 1) return ret; -- 2.55.0
