From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 25 Jul 2017 15:18:24 +0000 (-0700)
Subject: 3.18-stable patches
X-Git-Tag: v3.18.63~12
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e073cd9c0438cae2350591fad85bea16ee424c03;p=thirdparty%2Fkernel%2Fstable-queue.git

3.18-stable patches

added patches:
	kvm-ppc-book3s-hv-context-switch-ebb-registers-properly.patch
---

diff --git a/queue-3.18/kvm-ppc-book3s-hv-context-switch-ebb-registers-properly.patch b/queue-3.18/kvm-ppc-book3s-hv-context-switch-ebb-registers-properly.patch
new file mode 100644
index 00000000000..fda445e7b10
--- /dev/null
+++ b/queue-3.18/kvm-ppc-book3s-hv-context-switch-ebb-registers-properly.patch
@@ -0,0 +1,80 @@
+From ca8efa1df1d15a1795a2da57f9f6aada6ed6b946 Mon Sep 17 00:00:00 2001
+From: Paul Mackerras <paulus@ozlabs.org>
+Date: Tue, 6 Jun 2017 16:47:22 +1000
+Subject: KVM: PPC: Book3S HV: Context-switch EBB registers properly
+
+From: Paul Mackerras <paulus@ozlabs.org>
+
+commit ca8efa1df1d15a1795a2da57f9f6aada6ed6b946 upstream.
+
+This adds code to save the values of three SPRs (special-purpose
+registers) used by userspace to control event-based branches (EBBs),
+which are essentially interrupts that get delivered directly to
+userspace.  These registers are loaded up with guest values when
+entering the guest, and their values are saved when exiting the
+guest, but we were not saving the host values and restoring them
+before going back to userspace.
+
+On POWER8 this would only affect userspace programs which explicitly
+request the use of EBBs and also use the KVM_RUN ioctl, since the
+only source of EBBs on POWER8 is the PMU, and there is an explicit
+enable bit in the PMU registers (and those PMU registers do get
+properly context-switched between host and guest).  On POWER9 there
+is provision for externally-generated EBBs, and these are not subject
+to the control in the PMU registers.
+
+Since these registers only affect userspace, we can save them when
+we first come in from userspace and restore them before returning to
+userspace, rather than saving/restoring the host values on every
+guest entry/exit.  Similarly, we don't need to worry about their
+values on offline secondary threads since they execute in the context
+of the idle task, which never executes in userspace.
+
+Fixes: b005255e12a3 ("KVM: PPC: Book3S HV: Context-switch new POWER8 SPRs", 2014-01-08)
+Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+
+---
+ arch/powerpc/kvm/book3s_hv.c |   16 ++++++++++++++++
+ 1 file changed, 16 insertions(+)
+
+--- a/arch/powerpc/kvm/book3s_hv.c
++++ b/arch/powerpc/kvm/book3s_hv.c
+@@ -1950,6 +1950,7 @@ static int kvmppc_vcpu_run_hv(struct kvm
+ {
+ 	int r;
+ 	int srcu_idx;
++	unsigned long ebb_regs[3] = {};	/* shut up GCC */
+ 
+ 	if (!vcpu->arch.sane) {
+ 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
+@@ -1999,6 +2000,14 @@ static int kvmppc_vcpu_run_hv(struct kvm
+ 	flush_fp_to_thread(current);
+ 	flush_altivec_to_thread(current);
+ 	flush_vsx_to_thread(current);
++
++	/* Save userspace EBB register values */
++	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
++		ebb_regs[0] = mfspr(SPRN_EBBHR);
++		ebb_regs[1] = mfspr(SPRN_EBBRR);
++		ebb_regs[2] = mfspr(SPRN_BESCR);
++	}
++
+ 	vcpu->arch.wqp = &vcpu->arch.vcore->wq;
+ 	vcpu->arch.pgdir = current->mm->pgd;
+ 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
+@@ -2018,6 +2027,13 @@ static int kvmppc_vcpu_run_hv(struct kvm
+ 		}
+ 	} while (is_kvmppc_resume_guest(r));
+ 
++	/* Restore userspace EBB register values */
++	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
++		mtspr(SPRN_EBBHR, ebb_regs[0]);
++		mtspr(SPRN_EBBRR, ebb_regs[1]);
++		mtspr(SPRN_BESCR, ebb_regs[2]);
++	}
++
+  out:
+ 	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
+ 	atomic_dec(&vcpu->kvm->arch.vcpus_running);
diff --git a/queue-3.18/series b/queue-3.18/series
index b23734f792d..7aa885fe42c 100644
--- a/queue-3.18/series
+++ b/queue-3.18/series
@@ -52,3 +52,4 @@ staging-rtl8188eu-add-tl-wn722n-v2-support.patch
 drm-mst-fix-error-handling-during-mst-sideband-message-reception.patch
 drm-mst-avoid-dereferencing-a-null-mstb-in-drm_dp_mst_handle_up_req.patch
 drm-mst-avoid-processing-partially-received-up-down-message-transactions.patch
+kvm-ppc-book3s-hv-context-switch-ebb-registers-properly.patch