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arm64: KVM: Add access handler for PMCR register

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Add reset handler which gets host value of PMCR_EL0 and make writable
bits architecturally UNKNOWN except PMCR.E which is zero. Add an access
handler for PMCR.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Shannon Zhao 2015-06-18 16:01:53 +08:00 committed by Marc Zyngier
parent 04fe472615
commit ab9468340d
3 changed files with 47 additions and 2 deletions
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3
arch/arm64/include/asm/kvm_host.h
View File

@ -117,6 +117,9 @@ enum vcpu_sysreg {
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
/* 32bit specific registers. Keep them at the end of the range */
DACR32_EL2, /* Domain Access Control Register */
IFSR32_EL2, /* Instruction Fault Status Register */

42
arch/arm64/kvm/sys_regs.c
View File

@ -34,6 +34,7 @@
#include <asm/kvm_emulate.h>
#include <asm/kvm_host.h>
#include <asm/kvm_mmu.h>
#include <asm/perf_event.h>
#include <trace/events/kvm.h>
@ -439,6 +440,43 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
vcpu_sys_reg(vcpu, MPIDR_EL1) = (1ULL << 31) | mpidr;
}
static void reset_pmcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 pmcr, val;
asm volatile("mrs %0, pmcr_el0\n" : "=r" (pmcr));
/* Writable bits of PMCR_EL0 (ARMV8_PMU_PMCR_MASK) is reset to UNKNOWN
* except PMCR.E resetting to zero.
*/
val = ((pmcr & ~ARMV8_PMU_PMCR_MASK)
| (ARMV8_PMU_PMCR_MASK & 0xdecafbad)) & (~ARMV8_PMU_PMCR_E);
vcpu_sys_reg(vcpu, PMCR_EL0) = val;
}
static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
u64 val;
if (!kvm_arm_pmu_v3_ready(vcpu))
return trap_raz_wi(vcpu, p, r);
if (p->is_write) {
/* Only update writeable bits of PMCR */
val = vcpu_sys_reg(vcpu, PMCR_EL0);
val &= ~ARMV8_PMU_PMCR_MASK;
val |= p->regval & ARMV8_PMU_PMCR_MASK;
vcpu_sys_reg(vcpu, PMCR_EL0) = val;
} else {
/* PMCR.P & PMCR.C are RAZ */
val = vcpu_sys_reg(vcpu, PMCR_EL0)
& ~(ARMV8_PMU_PMCR_P | ARMV8_PMU_PMCR_C);
p->regval = val;
}
return true;
}
/* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */
#define DBG_BCR_BVR_WCR_WVR_EL1(n) \
/* DBGBVRn_EL1 */ \
@ -623,7 +661,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
/* PMCR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b000),
trap_raz_wi },
access_pmcr, reset_pmcr, },
/* PMCNTENSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
trap_raz_wi },
@ -885,7 +923,7 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1( 0), CRn( 7), CRm(14), Op2( 2), access_dcsw },
/* PMU */
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmcr },
{ 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 },

4
include/kvm/arm_pmu.h
View File

@ -34,9 +34,13 @@ struct kvm_pmu {
struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS];
bool ready;
};
#define kvm_arm_pmu_v3_ready(v) ((v)->arch.pmu.ready)
#else
struct kvm_pmu {
};
#define kvm_arm_pmu_v3_ready(v) (false)
#endif
#endif