[PATCH v2 1/9] arm64: KVM: rename pm_fake handler to trap_raz_wi

Marc Zyngier
2014-05-20T16:55:54Z

pm_fake doesn't quite describe what the handler does (ignoring writes
and returning 0 for reads).

As we're about to use it (a lot) in a different context, rename it
with a (admitedly cryptic) name that make sense for all users.

Reviewed-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/kvm/sys_regs.c | 83 ++++++++++++++++++++++++-----------------------
1 file changed, 43 insertions(+), 40 deletions(-)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 0324458..c3d28f1 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -163,18 +163,9 @@ static bool access_sctlr(struct kvm_vcpu *vcpu,
return true;
}

-/*
- * We could trap ID_DFR0 and tell the guest we don't support performance
- * monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was
- * NAKed, so it will read the PMCR anyway.
- *
- * Therefore we tell the guest we have 0 counters. Unfortunately, we
- * must always support PMCCNTR (the cycle counter): we just RAZ/WI for
- * all PM registers, which doesn't crash the guest kernel at least.
- */
-static bool pm_fake(struct kvm_vcpu *vcpu,
- const struct sys_reg_params *p,
- const struct sys_reg_desc *r)
+static bool trap_raz_wi(struct kvm_vcpu *vcpu,
+ const struct sys_reg_params *p,
+ const struct sys_reg_desc *r)
{
if (p->is_write)
return ignore_write(vcpu, p);
@@ -201,6 +192,17 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
/*
* Architected system registers.
* Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2
+ *
+ * We could trap ID_DFR0 and tell the guest we don't support performance
+ * monitoring. Unfortunately the patch to make the kernel check ID_DFR0 was
+ * NAKed, so it will read the PMCR anyway.
+ *
+ * Therefore we tell the guest we have 0 counters. Unfortunately, we
+ * must always support PMCCNTR (the cycle counter): we just RAZ/WI for
+ * all PM registers, which doesn't crash the guest kernel at least.
+ *
+ * Same goes for the whole debug infrastructure, which probably breaks
+ * some guest functionnality. This should be fixed.
*/
static const struct sys_reg_desc sys_reg_descs[] = {
/* DC ISW */
@@ -260,10 +262,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {

/* PMINTENSET_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b001),
- pm_fake },
+ trap_raz_wi },
/* PMINTENCLR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1001), CRm(0b1110), Op2(0b010),
- pm_fake },
+ trap_raz_wi },

/* MAIR_EL1 */
{ Op0(0b11), Op1(0b000), CRn(0b1010), CRm(0b0010), Op2(0b000),
@@ -292,43 +294,43 @@ static const struct sys_reg_desc sys_reg_descs[] = {

/* PMCR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000),
- pm_fake },
+ trap_raz_wi },
/* PMCNTENSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
- pm_fake },
+ trap_raz_wi },
/* PMCNTENCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010),
- pm_fake },
+ trap_raz_wi },
/* PMOVSCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
- pm_fake },
+ trap_raz_wi },
/* PMSWINC_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b100),
- pm_fake },
+ trap_raz_wi },
/* PMSELR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b101),
- pm_fake },
+ trap_raz_wi },
/* PMCEID0_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b110),
- pm_fake },
+ trap_raz_wi },
/* PMCEID1_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b111),
- pm_fake },
+ trap_raz_wi },
/* PMCCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b000),
- pm_fake },
+ trap_raz_wi },
/* PMXEVTYPER_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b001),
- pm_fake },
+ trap_raz_wi },
/* PMXEVCNTR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1101), Op2(0b010),
- pm_fake },
+ trap_raz_wi },
/* PMUSERENR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b000),
- pm_fake },
+ trap_raz_wi },
/* PMOVSSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1110), Op2(0b011),
- pm_fake },
+ trap_raz_wi },

/* TPIDR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1101), CRm(0b0000), Op2(0b010),
@@ -374,19 +376,20 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn( 7), CRm(10), Op2( 2), access_dcsw },
{ Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },

- { Op1( 0), CRn( 9), CRm(12), Op2( 0), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 1), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 2), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 3), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 5), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 6), pm_fake },
- { Op1( 0), CRn( 9), CRm(12), Op2( 7), pm_fake },
- { Op1( 0), CRn( 9), CRm(13), Op2( 0), pm_fake },
- { Op1( 0), CRn( 9), CRm(13), Op2( 1), pm_fake },
- { Op1( 0), CRn( 9), CRm(13), Op2( 2), pm_fake },
- { Op1( 0), CRn( 9), CRm(14), Op2( 0), pm_fake },
- { Op1( 0), CRn( 9), CRm(14), Op2( 1), pm_fake },
- { Op1( 0), CRn( 9), CRm(14), Op2( 2), pm_fake },
+ /* PMU */
+ { Op1( 0), CRn( 9), CRm(12), Op2( 0), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 5), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 6), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 7), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 0), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 1), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(13), Op2( 2), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(14), Op2( 0), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(14), Op2( 1), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(14), Op2( 2), trap_raz_wi },

{ Op1( 0), CRn(10), CRm( 2), Op2( 0), access_vm_reg, NULL, c10_PRRR },
{ Op1( 0), CRn(10), CRm( 2), Op2( 1), access_vm_reg, NULL, c10_NMRR },
--
1.8.3.4