[PATCH v5 04/21] KVM: ARM64: Add reset and access handlers for PMCR_EL0 register
From: Marc Zyngier <hidden>
Date: 2015-12-07 13:28:09
Also in:
kvm, kvmarm
On 03/12/15 06:11, Shannon Zhao wrote:
quoted hunk ↗ jump to hunk
From: Shannon Zhao <redacted> Add reset handler which gets host value of PMCR_EL0 and make writable bits architecturally UNKNOWN except PMCR.E to zero. Add a common access handler for PMU registers which emulates writing and reading register and add emulation for PMCR. Signed-off-by: Shannon Zhao <redacted> --- arch/arm64/kvm/sys_regs.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 95 insertions(+), 2 deletions(-)diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 87a64e8..e020fe0 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c@@ -33,6 +33,7 @@ #include <asm/kvm_emulate.h> #include <asm/kvm_host.h> #include <asm/kvm_mmu.h> +#include <asm/pmu.h> #include <trace/events/kvm.h>@@ -446,6 +447,58 @@ 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_PMCR_MASK) is reset to UNKNOWN + * except PMCR.E resetting to zero. + */ + val = ((pmcr & ~ARMV8_PMCR_MASK) | (ARMV8_PMCR_MASK & 0xdecafbad)) + & (~ARMV8_PMCR_E); + vcpu_sys_reg(vcpu, r->reg) = val; +} + +/* PMU registers accessor. */ +static bool access_pmu_regs(struct kvm_vcpu *vcpu, + const struct sys_reg_params *p,
You may have noticed that this now generates a warning on 4.4-rc4, as you cannot have a const struct sys_reg_params anymore (we've changed a number of things there to solve another bug).
+ const struct sys_reg_desc *r)
+{
+ u64 val;
+
+ if (p->is_write) {
+ switch (r->reg) {
+ case PMCR_EL0: {
+ /* Only update writeable bits of PMCR */
+ val = vcpu_sys_reg(vcpu, r->reg);
+ val &= ~ARMV8_PMCR_MASK;
+ val |= *vcpu_reg(vcpu, p->Rt) & ARMV8_PMCR_MASK;vcpu_reg and ->Rt are now gone. To ease the transition, I've pushed a patch on top of this series to my kvm-arm64/pmu-v5 branch. Feel free to use it as a reference. M. -- Jazz is not dead. It just smells funny...