4.9-stable patches

added patches:
	kvm-ppc-book3s-hv-fix-trap-number-return-from-__kvmppc_vcore_entry.patch

diff --git a/queue-4.9/kvm-ppc-book3s-hv-fix-trap-number-return-from-__kvmppc_vcore_entry.patch b/queue-4.9/kvm-ppc-book3s-hv-fix-trap-number-return-from-__kvmppc_vcore_entry.patch
new file mode 100644 (file)
index 0000000..9e7cff6
--- /dev/null
+++ b/queue-4.9/kvm-ppc-book3s-hv-fix-trap-number-return-from-__kvmppc_vcore_entry.patch
@@ -0,0 +1,99 @@
+From a8b48a4dccea77e29462e59f1dbf0d5aa1ff167c Mon Sep 17 00:00:00 2001
+From: Paul Mackerras <paulus@ozlabs.org>
+Date: Wed, 7 Mar 2018 22:17:20 +1100
+Subject: KVM: PPC: Book3S HV: Fix trap number return from __kvmppc_vcore_entry
+
+From: Paul Mackerras <paulus@ozlabs.org>
+
+commit a8b48a4dccea77e29462e59f1dbf0d5aa1ff167c upstream.
+
+This fixes a bug where the trap number that is returned by
+__kvmppc_vcore_entry gets corrupted.  The effect of the corruption
+is that IPIs get ignored on POWER9 systems when the IPI is sent via
+a doorbell interrupt to a CPU which is executing in a KVM guest.
+The effect of the IPI being ignored is often that another CPU locks
+up inside smp_call_function_many() (and if that CPU is holding a
+spinlock, other CPUs then lock up inside raw_spin_lock()).
+
+The trap number is currently held in register r12 for most of the
+assembly-language part of the guest exit path.  In that path, we
+call kvmppc_subcore_exit_guest(), which is a C function, without
+restoring r12 afterwards.  Depending on the kernel config and the
+compiler, it may modify r12 or it may not, so some config/compiler
+combinations see the bug and others don't.
+
+To fix this, we arrange for the trap number to be stored on the
+stack from the 'guest_bypass:' label until the end of the function,
+then the trap number is loaded and returned in r12 as before.
+
+Cc: stable@vger.kernel.org # v4.8+
+Fixes: fd7bacbca47a ("KVM: PPC: Book3S HV: Fix TB corruption in guest exit path on HMI interrupt")
+Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ arch/powerpc/kvm/book3s_hv_rmhandlers.S |    8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
++++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+@@ -299,7 +299,6 @@ kvm_novcpu_exit:
+       stw     r12, STACK_SLOT_TRAP(r1)
+       bl      kvmhv_commence_exit
+       nop
+-      lwz     r12, STACK_SLOT_TRAP(r1)
+       b       kvmhv_switch_to_host
+ 
+ /*
+@@ -1023,6 +1022,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
+ 
+ secondary_too_late:
+       li      r12, 0
++      stw     r12, STACK_SLOT_TRAP(r1)
+       cmpdi   r4, 0
+       beq     11f
+       stw     r12, VCPU_TRAP(r4)
+@@ -1266,12 +1266,12 @@ mc_cont:
+       bl      kvmhv_accumulate_time
+ #endif
+ 
++      stw     r12, STACK_SLOT_TRAP(r1)
+       mr      r3, r12
+       /* Increment exit count, poke other threads to exit */
+       bl      kvmhv_commence_exit
+       nop
+       ld      r9, HSTATE_KVM_VCPU(r13)
+-      lwz     r12, VCPU_TRAP(r9)
+ 
+       /* Stop others sending VCPU interrupts to this physical CPU */
+       li      r0, -1
+@@ -1549,6 +1549,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+        * POWER7/POWER8 guest -> host partition switch code.
+        * We don't have to lock against tlbies but we do
+        * have to coordinate the hardware threads.
++       * Here STACK_SLOT_TRAP(r1) contains the trap number.
+        */
+ kvmhv_switch_to_host:
+       /* Secondary threads wait for primary to do partition switch */
+@@ -1599,11 +1600,11 @@ BEGIN_FTR_SECTION
+ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+ 
+       /* If HMI, call kvmppc_realmode_hmi_handler() */
++      lwz     r12, STACK_SLOT_TRAP(r1)
+       cmpwi   r12, BOOK3S_INTERRUPT_HMI
+       bne     27f
+       bl      kvmppc_realmode_hmi_handler
+       nop
+-      li      r12, BOOK3S_INTERRUPT_HMI
+       /*
+        * At this point kvmppc_realmode_hmi_handler would have resync-ed
+        * the TB. Hence it is not required to subtract guest timebase
+@@ -1678,6 +1679,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
+       li      r0, KVM_GUEST_MODE_NONE
+       stb     r0, HSTATE_IN_GUEST(r13)
+ 
++      lwz     r12, STACK_SLOT_TRAP(r1)        /* return trap # in r12 */
+       ld      r0, SFS+PPC_LR_STKOFF(r1)
+       addi    r1, r1, SFS
+       mtlr    r0

diff --git a/queue-4.9/series b/queue-4.9/series
index 07a3ebe88190daedbdf0e9551366a34905898534..8f5b07372c966189f73fcccc814fd114e9367130 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -11,3 +11,4 @@ soreuseport-initialise-timewait-reuseport-field.patch
 perf-remove-superfluous-allocation-error-check.patch
 tcp-fix-tcp_repair_queue-bound-checking.patch
 bdi-fix-oops-in-wb_workfn.patch
+kvm-ppc-book3s-hv-fix-trap-number-return-from-__kvmppc_vcore_entry.patch