Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-4.2-20190821' into staging

ppc patch queue for 2019-08-21

First ppc and spapr pull request for qemu-4.2.  Includes:
   * Some TCG emulation fixes and performance improvements
   * Support for the mffsl instruction in TCG
   * Added missing DPDES SPR
   * Some enhancements to the emulation of the XIVE interrupt
     controller
   * Cleanups to spapr MSI management
   * Some new suspend/resume infrastructure and a draft suspend
     implementation for spapr
   * New spapr hypercall for TPM communication (will be needed for
     secure guests under an Ultravisor)
   * Fix several memory leaks

And a few other assorted fixes.

# gpg: Signature made Wed 21 Aug 2019 08:24:44 BST
# gpg:                using RSA key 75F46586AE61A66CC44E87DC6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>" [full]
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>" [full]
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>" [full]
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>" [unknown]
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-4.2-20190821: (42 commits)
  ppc: Fix emulated single to double denormalized conversions
  ppc: Fix emulated INFINITY and NAN conversions
  ppc: conform to processor User's Manual for xscvdpspn
  ppc: Add support for 'mffsl' instruction
  target/ppc: Add Directed Privileged Door-bell Exception State (DPDES) SPR
  spapr/xive: Mask the EAS when allocating an IRQ
  spapr: Implement better workaround in spapr-vty device
  spapr/irq: Drop spapr_irq_msi_reset()
  spapr/pci: Free MSIs during reset
  spapr/pci: Consolidate de-allocation of MSIs
  ppc: remove idle_timer logic
  spapr: Implement ibm,suspend-me
  i386: use machine class ->wakeup method
  machine: Add wakeup method to MachineClass
  ppc/xive: Improve 'info pic' support
  ppc/xive: Provide silent escalation support
  ppc/xive: Provide unconditional escalation support
  ppc/xive: Provide escalation support
  ppc/xive: Provide backlog support
  ppc/xive: Implement TM_PULL_OS_CTX special command
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 18 deletions

diff --git a/hw/char/spapr_vty.c b/hw/char/spapr_vty.c
index 7f860fcce7..087c93e4fa 100644
--- a/hw/char/spapr_vty.c
+++ b/hw/char/spapr_vty.c
@@ -59,25 +59,19 @@ static int vty_getchars(SpaprVioDevice *sdev, uint8_t *buf, int max)
     int n = 0;
 
     while ((n < max) && (dev->out != dev->in)) {
-        buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
-
-        /* PowerVM's vty implementation has a bug where it inserts a
-         * \0 after every \r going to the guest.  Existing guests have
-         * a workaround for this which removes every \0 immediately
-         * following a \r, so here we make ourselves bug-for-bug
-         * compatible, so that the guest won't drop a real \0-after-\r
-         * that happens to occur in a binary stream. */
-        if (buf[n - 1] == '\r') {
-            if (n < max) {
-                buf[n++] = '\0';
-            } else {
-                /* No room for the extra \0, roll back and try again
-                 * next time */
-                dev->out--;
-                n--;
-                break;
-            }
+        /*
+         * Long ago, PowerVM's vty implementation had a bug where it
+         * inserted a \0 after every \r going to the guest.  Existing
+         * guests have a workaround for this which removes every \0
+         * immediately following a \r.  To avoid triggering this
+         * workaround, we stop before inserting a \0 if the preceding
+         * character in the output buffer is a \r.
+         */
+        if (n > 0 && (buf[n - 1] == '\r') &&
+                (dev->buf[dev->out % VTERM_BUFSIZE] == '\0')) {
+            break;
         }
+        buf[n++] = dev->buf[dev->out++ % VTERM_BUFSIZE];
     }
 
     qemu_chr_fe_accept_input(&dev->chardev);