From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v4 04/15] KVM: arm: common infrastructure for handling AArch32 CP14/CP15
Date: Wed, 2 Sep 2015 15:09:49 +0200 [thread overview]
Message-ID: <20150902130949.GK10991@cbox> (raw)
In-Reply-To: <1439213167-8988-5-git-send-email-zhichao.huang@linaro.org>
On Mon, Aug 10, 2015 at 09:25:56PM +0800, Zhichao Huang wrote:
> As we're about to trap a bunch of CP14 registers, let's rework
> the CP15 handling so it can be generalized and work with multiple
> tables.
>
> We stop trapping access here, because we haven't finished our trap
> handlers. We will enable trapping agian until everything is OK.
>
> Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org>
> ---
> arch/arm/kvm/coproc.c | 168 ++++++++++++++++++++++++++---------------
> arch/arm/kvm/interrupts_head.S | 2 +-
> 2 files changed, 110 insertions(+), 60 deletions(-)
>
> diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
> index 4db571d..d23395b 100644
> --- a/arch/arm/kvm/coproc.c
> +++ b/arch/arm/kvm/coproc.c
> @@ -375,6 +375,9 @@ static const struct coproc_reg cp15_regs[] = {
> { CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
> };
>
> +static const struct coproc_reg cp14_regs[] = {
> +};
> +
> /* Target specific emulation tables */
> static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
>
> @@ -424,43 +427,75 @@ static const struct coproc_reg *find_reg(const struct coproc_params *params,
> return NULL;
> }
>
> -static int emulate_cp15(struct kvm_vcpu *vcpu,
> - const struct coproc_params *params)
> +/*
> + * emulate_cp -- tries to match a cp14/cp15 access in a handling table,
> + * and call the corresponding trap handler.
> + *
> + * @params: pointer to the descriptor of the access
> + * @table: array of trap descriptors
> + * @num: size of the trap descriptor array
> + *
> + * Return 0 if the access has been handled, and -1 if not.
> + */
> +static int emulate_cp(struct kvm_vcpu *vcpu,
> + const struct coproc_params *params,
> + const struct coproc_reg *table,
> + size_t num)
> {
> - size_t num;
> - const struct coproc_reg *table, *r;
> -
> - trace_kvm_emulate_cp15_imp(params->Op1, params->Rt1, params->CRn,
> - params->CRm, params->Op2, params->is_write);
> + const struct coproc_reg *r;
>
> - table = get_target_table(vcpu->arch.target, &num);
> + if (!table)
> + return -1; /* Not handled */
>
> - /* Search target-specific then generic table. */
> r = find_reg(params, table, num);
> - if (!r)
> - r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));
>
> - if (likely(r)) {
> + if (r) {
> /* If we don't have an accessor, we should never get here! */
> BUG_ON(!r->access);
>
> if (likely(r->access(vcpu, params, r))) {
> /* Skip instruction, since it was emulated */
> kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> - return 1;
> }
> - /* If access function fails, it should complain. */
> - } else {
> - kvm_err("Unsupported guest CP15 access at: %08lx\n",
> - *vcpu_pc(vcpu));
> - print_cp_instr(params);
> +
> + /* Handled */
> + return 0;
> }
> +
> + /* Not handled */
> + return -1;
> +}
> +
> +static void unhandled_cp_access(struct kvm_vcpu *vcpu,
> + const struct coproc_params *params)
> +{
> + u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);
> + int cp;
> +
> + switch (hsr_ec) {
> + case HSR_EC_CP15_32:
> + case HSR_EC_CP15_64:
> + cp = 15;
> + break;
> + case HSR_EC_CP14_MR:
> + case HSR_EC_CP14_64:
> + cp = 14;
> + break;
> + default:
> + WARN_ON((cp = -1));
> + }
> +
> + kvm_err("Unsupported guest CP%d access at: %08lx\n",
> + cp, *vcpu_pc(vcpu));
> + print_cp_instr(params);
> kvm_inject_undefined(vcpu);
> - return 1;
> }
>
> -static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
> - bool cp15)
> +int kvm_handle_cp_64(struct kvm_vcpu *vcpu,
> + const struct coproc_reg *global,
> + size_t nr_global,
> + const struct coproc_reg *target_specific,
> + size_t nr_specific)
> {
> struct coproc_params params;
>
> @@ -474,37 +509,15 @@ static int kvm_handle_cp_64(struct kvm_vcpu *vcpu, struct kvm_run *run,
> params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf;
> params.CRm = 0;
>
> - if (cp15)
> - return emulate_cp15(vcpu, ¶ms);
> + if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific))
> + return 1;
> + if (!emulate_cp(vcpu, ¶ms, global, nr_global))
> + return 1;
>
> - /* raz_wi cp14 */
> - (void)trap_raz_wi(vcpu, ¶ms, NULL);
> -
> - /* handled */
> - kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> + unhandled_cp_access(vcpu, ¶ms);
> return 1;
> }
>
> -/**
> - * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
> - * @vcpu: The VCPU pointer
> - * @run: The kvm_run struct
> - */
> -int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> -{
> - return kvm_handle_cp_64(vcpu, run, 1);
> -}
> -
> -/**
> - * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
> - * @vcpu: The VCPU pointer
> - * @run: The kvm_run struct
> - */
> -int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> -{
> - return kvm_handle_cp_64(vcpu, run, 0);
> -}
> -
> static void reset_coproc_regs(struct kvm_vcpu *vcpu,
> const struct coproc_reg *table, size_t num)
> {
> @@ -515,8 +528,11 @@ static void reset_coproc_regs(struct kvm_vcpu *vcpu,
> table[i].reset(vcpu, &table[i]);
> }
>
> -static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
> - bool cp15)
> +int kvm_handle_cp_32(struct kvm_vcpu *vcpu,
> + const struct coproc_reg *global,
> + size_t nr_global,
> + const struct coproc_reg *target_specific,
> + size_t nr_specific)
> {
> struct coproc_params params;
>
> @@ -530,25 +546,57 @@ static int kvm_handle_cp_32(struct kvm_vcpu *vcpu, struct kvm_run *run,
> params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7;
> params.Rt2 = 0;
>
> - if (cp15)
> - return emulate_cp15(vcpu, ¶ms);
> -
> - /* raz_wi cp14 */
> - (void)trap_raz_wi(vcpu, ¶ms, NULL);
> + if (!emulate_cp(vcpu, ¶ms, target_specific, nr_specific))
> + return 1;
> + if (!emulate_cp(vcpu, ¶ms, global, nr_global))
> + return 1;
>
> - /* handled */
> - kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
> + unhandled_cp_access(vcpu, ¶ms);
> return 1;
> }
>
> /**
> + * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access
> + * @vcpu: The VCPU pointer
> + * @run: The kvm_run struct
> + */
> +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +{
> + const struct coproc_reg *target_specific;
> + size_t num;
> +
> + target_specific = get_target_table(vcpu->arch.target, &num);
> + return kvm_handle_cp_64(vcpu,
> + cp15_regs, ARRAY_SIZE(cp15_regs),
> + target_specific, num);
> +}
> +
> +/**
> * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access
> * @vcpu: The VCPU pointer
> * @run: The kvm_run struct
> */
> int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> {
> - return kvm_handle_cp_32(vcpu, run, 1);
> + const struct coproc_reg *target_specific;
> + size_t num;
> +
> + target_specific = get_target_table(vcpu->arch.target, &num);
> + return kvm_handle_cp_32(vcpu,
> + cp15_regs, ARRAY_SIZE(cp15_regs),
> + target_specific, num);
> +}
> +
> +/**
> + * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access
> + * @vcpu: The VCPU pointer
> + * @run: The kvm_run struct
> + */
> +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)
> +{
> + return kvm_handle_cp_64(vcpu,
> + cp14_regs, ARRAY_SIZE(cp14_regs),
> + NULL, 0);
> }
>
> /**
> @@ -558,7 +606,9 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> */
> int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)
> {
> - return kvm_handle_cp_32(vcpu, run, 0);
> + return kvm_handle_cp_32(vcpu,
> + cp14_regs, ARRAY_SIZE(cp14_regs),
> + NULL, 0);
> }
>
> /******************************************************************************
> diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
> index 7c4075c..7ac5e51 100644
> --- a/arch/arm/kvm/interrupts_head.S
> +++ b/arch/arm/kvm/interrupts_head.S
> @@ -633,7 +633,7 @@ ARM_BE8(rev r6, r6 )
> * (hardware reset value is 0) */
> .macro set_hdcr operation
> mrc p15, 4, r2, c1, c1, 1
> - ldr r3, =(HDCR_TPM|HDCR_TPMCR|HDCR_TDRA|HDCR_TDOSA|HDCR_TDA)
> + ldr r3, =(HDCR_TPM|HDCR_TPMCR)
I know I said ok to this, but I don't like the ordering of this with
these patches.
I think we should only stop trapping debug accesses when we have proper
world-switching in place.
You should be able to put all the infrastructure needed in place first,
and then hook things up in the end.
Thanks,
-Christoffer
> .if \operation == vmentry
> orr r2, r2, r3 @ Trap some perfmon accesses
> .else
> --
> 1.7.12.4
>
next prev parent reply other threads:[~2015-09-02 13:09 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-10 13:25 [PATCH v4 00/15] KVM: arm: debug infrastructure support Zhichao Huang
2015-08-10 13:25 ` [PATCH v4 01/15] KVM: arm: plug guest debug exploit Zhichao Huang
2015-09-02 11:38 ` Christoffer Dall
2015-09-29 5:13 ` Zhichao Huang
2015-08-10 13:25 ` [PATCH v4 02/15] KVM: arm: rename pm_fake handler to trap_raz_wi Zhichao Huang
2015-08-10 13:25 ` [PATCH v4 03/15] KVM: arm: enable to use the ARM_DSCR_MDBGEN macro from KVM assembly code Zhichao Huang
2015-08-10 13:25 ` [PATCH v4 04/15] KVM: arm: common infrastructure for handling AArch32 CP14/CP15 Zhichao Huang
2015-09-02 13:09 ` Christoffer Dall [this message]
2015-08-10 13:25 ` [PATCH v4 05/15] KVM: arm: check ordering of all system register tables Zhichao Huang
2015-08-10 13:25 ` [PATCH v4 06/15] KVM: arm: add trap handlers for 32-bit debug registers Zhichao Huang
2015-09-02 16:03 ` Christoffer Dall
2015-08-10 13:25 ` [PATCH v4 07/15] KVM: arm: add trap handlers for 64-bit " Zhichao Huang
2015-08-10 13:26 ` [PATCH v4 08/15] KVM: arm: add a trace event for cp14 traps Zhichao Huang
2015-08-10 13:26 ` [PATCH v4 09/15] KVM: arm: redefine kvm_cpu_context_t to save the host cp14 states Zhichao Huang
2015-09-02 14:54 ` Christoffer Dall
2015-08-10 13:26 ` [PATCH v4 10/15] KVM: arm: implement world switch for debug registers Zhichao Huang
2015-09-02 14:53 ` Christoffer Dall
2015-09-29 5:32 ` Zhichao Huang
2015-09-29 7:34 ` Christoffer Dall
2015-08-10 13:26 ` [PATCH v4 11/15] KVM: arm: add a function to keep track of host use of the " Zhichao Huang
2015-09-02 15:40 ` Christoffer Dall
2015-08-10 13:26 ` [PATCH v4 12/15] KVM: arm: " Zhichao Huang
2015-09-02 15:44 ` Christoffer Dall
2015-08-10 13:26 ` [PATCH v4 13/15] KVM: arm: keep track of guest " Zhichao Huang
2015-09-02 16:01 ` Christoffer Dall
2015-09-29 5:36 ` Zhichao Huang
2015-08-10 13:26 ` [PATCH v4 14/15] KVM: arm: implement lazy world switch for " Zhichao Huang
2015-09-02 16:06 ` Christoffer Dall
2015-08-10 13:26 ` [PATCH v4 15/15] KVM: arm: enable trapping of all " Zhichao Huang
2015-09-02 16:08 ` Christoffer Dall
2015-09-29 5:41 ` Zhichao Huang
2015-09-29 7:38 ` Christoffer Dall
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