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-rw-r--r--arch/powerpc/kernel/exceptions-64s.S4
-rw-r--r--arch/powerpc/kernel/module.c2
-rw-r--r--arch/powerpc/kernel/setup_64.c28
-rw-r--r--arch/powerpc/kernel/time.c29
-rw-r--r--arch/powerpc/kernel/vdso/gettimeofday.S9
5 files changed, 54 insertions, 18 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 55caeee37c08..b66dd6f775a4 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -809,6 +809,10 @@ __start_interrupts:
* - MSR_EE|MSR_RI is clear (no reentrant exceptions)
* - Standard kernel environment is set up (stack, paca, etc)
*
+ * KVM:
+ * These interrupts do not elevate HV 0->1, so HV is not involved. PR KVM
+ * ensures that FSCR[SCV] is disabled whenever it has to force AIL off.
+ *
* Call convention:
*
* syscall register convention is in Documentation/powerpc/syscall64-abi.rst
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index 40a583e9d3c7..97a76a8619fb 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -101,7 +101,7 @@ __module_alloc(unsigned long size, unsigned long start, unsigned long end, bool
* too.
*/
return __vmalloc_node_range(size, 1, start, end, gfp, prot,
- VM_FLUSH_RESET_PERMS | VM_NO_HUGE_VMAP,
+ VM_FLUSH_RESET_PERMS,
NUMA_NO_NODE, __builtin_return_address(0));
}
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index e547066a06aa..a96f05063bc9 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -196,6 +196,34 @@ static void __init configure_exceptions(void)
/* Under a PAPR hypervisor, we need hypercalls */
if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
+ /*
+ * - PR KVM does not support AIL mode interrupts in the host
+ * while a PR guest is running.
+ *
+ * - SCV system call interrupt vectors are only implemented for
+ * AIL mode interrupts.
+ *
+ * - On pseries, AIL mode can only be enabled and disabled
+ * system-wide so when a PR VM is created on a pseries host,
+ * all CPUs of the host are set to AIL=0 mode.
+ *
+ * - Therefore host CPUs must not execute scv while a PR VM
+ * exists.
+ *
+ * - SCV support can not be disabled dynamically because the
+ * feature is advertised to host userspace. Disabling the
+ * facility and emulating it would be possible but is not
+ * implemented.
+ *
+ * - So SCV support is blanket disabled if PR KVM could possibly
+ * run. That is, PR support compiled in, booting on pseries
+ * with hash MMU.
+ */
+ if (IS_ENABLED(CONFIG_KVM_BOOK3S_PR_POSSIBLE) && !radix_enabled()) {
+ init_task.thread.fscr &= ~FSCR_SCV;
+ cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_SCV;
+ }
+
/* Enable AIL if possible */
if (!pseries_enable_reloc_on_exc()) {
init_task.thread.fscr &= ~FSCR_SCV;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f5cbfe5efd25..f80cce0e3899 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -615,23 +615,22 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
return;
}
- /* Conditionally hard-enable interrupts. */
- if (should_hard_irq_enable()) {
- /*
- * Ensure a positive value is written to the decrementer, or
- * else some CPUs will continue to take decrementer exceptions.
- * When the PPC_WATCHDOG (decrementer based) is configured,
- * keep this at most 31 bits, which is about 4 seconds on most
- * systems, which gives the watchdog a chance of catching timer
- * interrupt hard lockups.
- */
- if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
- set_dec(0x7fffffff);
- else
- set_dec(decrementer_max);
+ /*
+ * Ensure a positive value is written to the decrementer, or
+ * else some CPUs will continue to take decrementer exceptions.
+ * When the PPC_WATCHDOG (decrementer based) is configured,
+ * keep this at most 31 bits, which is about 4 seconds on most
+ * systems, which gives the watchdog a chance of catching timer
+ * interrupt hard lockups.
+ */
+ if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
+ set_dec(0x7fffffff);
+ else
+ set_dec(decrementer_max);
+ /* Conditionally hard-enable interrupts. */
+ if (should_hard_irq_enable())
do_hard_irq_enable();
- }
#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
if (atomic_read(&ppc_n_lost_interrupts) != 0)
diff --git a/arch/powerpc/kernel/vdso/gettimeofday.S b/arch/powerpc/kernel/vdso/gettimeofday.S
index eb9c81e1c218..0c4ecc8fec5a 100644
--- a/arch/powerpc/kernel/vdso/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso/gettimeofday.S
@@ -22,12 +22,15 @@
.macro cvdso_call funct call_time=0
.cfi_startproc
PPC_STLU r1, -PPC_MIN_STKFRM(r1)
+ .cfi_adjust_cfa_offset PPC_MIN_STKFRM
mflr r0
- .cfi_register lr, r0
PPC_STLU r1, -PPC_MIN_STKFRM(r1)
+ .cfi_adjust_cfa_offset PPC_MIN_STKFRM
PPC_STL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
+ .cfi_rel_offset lr, PPC_MIN_STKFRM + PPC_LR_STKOFF
#ifdef __powerpc64__
PPC_STL r2, PPC_MIN_STKFRM + STK_GOT(r1)
+ .cfi_rel_offset r2, PPC_MIN_STKFRM + STK_GOT
#endif
get_datapage r5
.ifeq \call_time
@@ -39,13 +42,15 @@
PPC_LL r0, PPC_MIN_STKFRM + PPC_LR_STKOFF(r1)
#ifdef __powerpc64__
PPC_LL r2, PPC_MIN_STKFRM + STK_GOT(r1)
+ .cfi_restore r2
#endif
.ifeq \call_time
cmpwi r3, 0
.endif
mtlr r0
- .cfi_restore lr
addi r1, r1, 2 * PPC_MIN_STKFRM
+ .cfi_restore lr
+ .cfi_def_cfa_offset 0
crclr so
.ifeq \call_time
beqlr+