kvm: Add KVM_PFN_ERR_SIGPENDING

Add a new pfn error to show that we've got a pending signal to handle
during hva_to_pfn_slow() procedure (of -EINTR retval).

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20221011195809.557016-3-peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 18592bd..911b064 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -96,6 +96,7 @@
 #define KVM_PFN_ERR_FAULT      (KVM_PFN_ERR_MASK)
 #define KVM_PFN_ERR_HWPOISON   (KVM_PFN_ERR_MASK + 1)
 #define KVM_PFN_ERR_RO_FAULT   (KVM_PFN_ERR_MASK + 2)
+#define KVM_PFN_ERR_SIGPENDING (KVM_PFN_ERR_MASK + 3)
 
 /*
  * error pfns indicate that the gfn is in slot but faild to
@@ -107,6 +108,15 @@ static inline bool is_error_pfn(kvm_pfn_t pfn)
 }
 
 /*
+ * KVM_PFN_ERR_SIGPENDING indicates that fetching the PFN was interrupted
+ * by a pending signal.  Note, the signal may or may not be fatal.
+ */
+static inline bool is_sigpending_pfn(kvm_pfn_t pfn)
+{
+       return pfn == KVM_PFN_ERR_SIGPENDING;
+}
+
+/*
  * error_noslot pfns indicate that the gfn can not be
  * translated to pfn - it is not in slot or failed to
  * translate it to pfn.

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 25d7872..558f52d 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2667,6 +2667,8 @@ kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async,
        npages = hva_to_pfn_slow(addr, async, write_fault, writable, &pfn);
        if (npages == 1)
                return pfn;
+       if (npages == -EINTR)
+               return KVM_PFN_ERR_SIGPENDING;
 
        mmap_read_lock(current->mm);
        if (npages == -EHWPOISON ||