Merge remote-tracking branch 'remotes/yongbok/tags/mips-20170803' into staging

MIPS patches 2017-08-03

Changes:
KVM T&E segment support for TCG
malta: leave space for the bootmap after the initrd
Apply CP0.PageMask before writing into TLB entry
Fix fallout from indirect branch optimisation

# gpg: Signature made Thu 03 Aug 2017 15:32:59 BST
# gpg:                using RSA key 0x2238EB86D5F797C2
# gpg: Good signature from "Yongbok Kim <yongbok.kim@imgtec.com>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg:          It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 8600 4CF5 3415 A5D9 4CFA  2B5C 2238 EB86 D5F7 97C2

* remotes/yongbok/tags/mips-20170803:
  target/mips: Fix RDHWR CC with icount
  target/mips: Drop redundant gen_io_start/stop()
  target/mips: Use BS_EXCP where interrupts are expected
  target-mips: apply CP0.PageMask before writing into TLB entry
  mips: Add KVM T&E segment support for TCG
  mips: Improve segment defs for KVM T&E guests
  mips/malta: leave space for the bootmap after the initrd
  target-mips: Don't stop on [d]mtc0 DESAVE/KScratch

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

2 files changed, 23 insertions, 11 deletions

diff --git a/hw/mips/addr.c b/hw/mips/addr.c
index e4e86b4a75..4da46e1731 100644
--- a/hw/mips/addr.c
+++ b/hw/mips/addr.c
@@ -24,6 +24,8 @@
 #include "hw/hw.h"
 #include "hw/mips/cpudevs.h"
 
+static int mips_um_ksegs;
+
 uint64_t cpu_mips_kseg0_to_phys(void *opaque, uint64_t addr)
 {
     return addr & 0x1fffffffll;
@@ -38,3 +40,13 @@ uint64_t cpu_mips_kvm_um_phys_to_kseg0(void *opaque, uint64_t addr)
 {
     return addr | 0x40000000ll;
 }
+
+bool mips_um_ksegs_enabled(void)
+{
+    return mips_um_ksegs;
+}
+
+void mips_um_ksegs_enable(void)
+{
+    mips_um_ksegs = 1;
+}
diff --git a/hw/mips/mips_malta.c b/hw/mips/mips_malta.c
index 8ecd544baa..af678f5784 100644
--- a/hw/mips/mips_malta.c
+++ b/hw/mips/mips_malta.c
@@ -818,23 +818,20 @@ static int64_t load_kernel (void)
         exit(1);
     }
 
-    /* Sanity check where the kernel has been linked */
-    if (kvm_enabled()) {
-        if (kernel_entry & 0x80000000ll) {
+    /* Check where the kernel has been linked */
+    if (kernel_entry & 0x80000000ll) {
+        if (kvm_enabled()) {
             error_report("KVM guest kernels must be linked in useg. "
                          "Did you forget to enable CONFIG_KVM_GUEST?");
             exit(1);
         }
 
-        xlate_to_kseg0 = cpu_mips_kvm_um_phys_to_kseg0;
+        xlate_to_kseg0 = cpu_mips_phys_to_kseg0;
     } else {
-        if (!(kernel_entry & 0x80000000ll)) {
-            error_report("KVM guest kernels aren't supported with TCG. "
-                         "Did you unintentionally enable CONFIG_KVM_GUEST?");
-            exit(1);
-        }
+        /* if kernel entry is in useg it is probably a KVM T&E kernel */
+        mips_um_ksegs_enable();
 
-        xlate_to_kseg0 = cpu_mips_phys_to_kseg0;
+        xlate_to_kseg0 = cpu_mips_kvm_um_phys_to_kseg0;
     }
 
     /* load initrd */
@@ -843,7 +840,10 @@ static int64_t load_kernel (void)
     if (loaderparams.initrd_filename) {
         initrd_size = get_image_size (loaderparams.initrd_filename);
         if (initrd_size > 0) {
-            initrd_offset = (loaderparams.ram_low_size - initrd_size
+            /* The kernel allocates the bootmap memory in the low memory after
+               the initrd.  It takes at most 128kiB for 2GB RAM and 4kiB
+               pages.  */
+            initrd_offset = (loaderparams.ram_low_size - initrd_size - 131072
                              - ~INITRD_PAGE_MASK) & INITRD_PAGE_MASK;
             if (kernel_high >= initrd_offset) {
                 fprintf(stderr,