On 03/12/15 06:11, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
>
> 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 <shannon.zhao@xxxxxxxxxx>
> ---
> 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...
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