From: Maxim Levitsky <mlevitsk@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: seanjc@google.com
Subject: Re: [PATCH 09/13] KVM: x86: move all vcpu->arch.pio* setup in emulator_pio_in_out
Date: Tue, 26 Oct 2021 16:56:12 +0300 [thread overview]
Message-ID: <5b16ea6020ec429c845fd65dfcb169700619867a.camel@redhat.com> (raw)
In-Reply-To: <20211022153616.1722429-10-pbonzini@redhat.com>
On Fri, 2021-10-22 at 11:36 -0400, Paolo Bonzini wrote:
> For now, this is basically an excuse to add back the void* argument to
> the function, while removing some knowledge of vcpu->arch.pio* from
> its callers. The WARN that vcpu->arch.pio.count is zero is also
> extended to OUT operations.
>
> We cannot do more as long as we have __emulator_pio_in always followed
> by complete_emulator_pio_in, which uses the vcpu->arch.pio* fields.
> But after fixing that, it will be possible to only populate the
> vcpu->arch.pio* fields on userspace exits.
>
> No functional change intended.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> arch/x86/kvm/trace.h | 2 +-
> arch/x86/kvm/x86.c | 18 ++++++++++--------
> 2 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
> index 03ebe368333e..1b0167ae9e24 100644
> --- a/arch/x86/kvm/trace.h
> +++ b/arch/x86/kvm/trace.h
> @@ -152,7 +152,7 @@ TRACE_EVENT(kvm_xen_hypercall,
>
> TRACE_EVENT(kvm_pio,
> TP_PROTO(unsigned int rw, unsigned int port, unsigned int size,
> - unsigned int count, void *data),
> + unsigned int count, const void *data),
> TP_ARGS(rw, port, size, count, data),
>
> TP_STRUCT__entry(
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index d6b8df7cea80..7c421d9fbcb6 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6887,17 +6887,22 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
> }
>
> static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
> - unsigned short port,
> + unsigned short port, void *data,
> unsigned int count, bool in)
> {
> - void *data = vcpu->arch.pio_data;
> unsigned i;
> int r;
>
> + WARN_ON_ONCE(vcpu->arch.pio.count);
> vcpu->arch.pio.port = port;
> vcpu->arch.pio.in = in;
> vcpu->arch.pio.count = count;
> vcpu->arch.pio.size = size;
It won't hurt to add the assert that size * count < PAGE_SIZE here.
> + if (in)
> + memset(vcpu->arch.pio_data, 0, size * count);
> + else
> + memcpy(vcpu->arch.pio_data, data, size * count);
> + data = vcpu->arch.pio_data;
>
> for (i = 0; i < count; i++) {
> if (in)
> @@ -6925,9 +6930,7 @@ static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
> static int __emulator_pio_in(struct kvm_vcpu *vcpu, int size,
> unsigned short port, unsigned int count)
> {
> - WARN_ON(vcpu->arch.pio.count);
> - memset(vcpu->arch.pio_data, 0, size * count);
> - return emulator_pio_in_out(vcpu, size, port, count, true);
> + return emulator_pio_in_out(vcpu, size, port, NULL, count, true);
> }
>
> static void complete_emulator_pio_in(struct kvm_vcpu *vcpu, void *val)
> @@ -6971,9 +6974,8 @@ static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
> {
> int ret;
>
> - memcpy(vcpu->arch.pio_data, val, size * count);
> - trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
> - ret = emulator_pio_in_out(vcpu, size, port, count, false);
> + trace_kvm_pio(KVM_PIO_OUT, port, size, count, val);
> + ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
> if (ret)
> vcpu->arch.pio.count = 0;
>
Makes sense.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards,
Maxim Levitsky
next prev parent reply other threads:[~2021-10-26 13:56 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 15:36 [PATCH v2 00/13] fixes and cleanups for string I/O emulation Paolo Bonzini
2021-10-22 15:36 ` [PATCH 01/13] KVM: SEV-ES: rename guest_ins_data to sev_pio_data Paolo Bonzini
2021-10-22 15:36 ` [PATCH 02/13] KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out Paolo Bonzini
2021-10-22 15:36 ` [PATCH 03/13] KVM: SEV-ES: clean up kvm_sev_es_ins/outs Paolo Bonzini
2021-10-22 15:36 ` [PATCH 04/13] KVM: x86: split the two parts of emulator_pio_in Paolo Bonzini
2021-10-22 15:36 ` [PATCH 05/13] KVM: x86: remove unnecessary arguments from complete_emulator_pio_in Paolo Bonzini
2021-10-22 15:36 ` [PATCH 06/13] KVM: SEV-ES: keep INS functions together Paolo Bonzini
2021-10-22 15:36 ` [PATCH 07/13] KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed Paolo Bonzini
2021-10-22 15:36 ` [PATCH 08/13] KVM: x86: inline kernel_pio into its sole caller Paolo Bonzini
2021-10-26 13:55 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 09/13] KVM: x86: move all vcpu->arch.pio* setup in emulator_pio_in_out Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky [this message]
2021-10-22 15:36 ` [PATCH 10/13] KVM: x86: wean in-kernel PIO from vcpu->arch.pio* Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 11/13] KVM: x86: wean fast IN from emulator_pio_in Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 12/13] KVM: x86: de-underscorify __emulator_pio_in Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 13/13] KVM: SEV-ES: reuse advance_sev_es_emulated_ins for OUT too Paolo Bonzini
2021-10-26 13:57 ` Maxim Levitsky
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