lkml.org 
[lkml]   [2021]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC PATCH v2 14/69] KVM: x86: Split core of hypercall emulation to helper function
From
Date
On 03/07/21 00:04, isaku.yamahata@intel.com wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> By necessity, TDX will use a different register ABI for hypercalls.
> Break out the core functionality so that it may be reused for TDX.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
> ---
> arch/x86/include/asm/kvm_host.h | 4 +++
> arch/x86/kvm/x86.c | 55 ++++++++++++++++++++-------------
> 2 files changed, 38 insertions(+), 21 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 9c7ced0e3171..80b943e4ab6d 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1667,6 +1667,10 @@ void kvm_vcpu_update_apicv(struct kvm_vcpu *vcpu);
> void kvm_request_apicv_update(struct kvm *kvm, bool activate,
> unsigned long bit);
>
> +unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr,
> + unsigned long a0, unsigned long a1,
> + unsigned long a2, unsigned long a3,
> + int op_64_bit);
> int kvm_emulate_hypercall(struct kvm_vcpu *vcpu);
>
> int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index d11cf87674f3..795f83a1cf9a 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -8406,26 +8406,15 @@ static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id)
> return;
> }
>
> -int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> +unsigned long __kvm_emulate_hypercall(struct kvm_vcpu *vcpu, unsigned long nr,
> + unsigned long a0, unsigned long a1,
> + unsigned long a2, unsigned long a3,
> + int op_64_bit)
> {
> - unsigned long nr, a0, a1, a2, a3, ret;
> - int op_64_bit;
> -
> - if (kvm_xen_hypercall_enabled(vcpu->kvm))
> - return kvm_xen_hypercall(vcpu);
> -
> - if (kvm_hv_hypercall_enabled(vcpu))
> - return kvm_hv_hypercall(vcpu);
> -
> - nr = kvm_rax_read(vcpu);
> - a0 = kvm_rbx_read(vcpu);
> - a1 = kvm_rcx_read(vcpu);
> - a2 = kvm_rdx_read(vcpu);
> - a3 = kvm_rsi_read(vcpu);
> + unsigned long ret;
>
> trace_kvm_hypercall(nr, a0, a1, a2, a3);
>
> - op_64_bit = is_64_bit_mode(vcpu);
> if (!op_64_bit) {
> nr &= 0xFFFFFFFF;
> a0 &= 0xFFFFFFFF;
> @@ -8434,11 +8423,6 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> a3 &= 0xFFFFFFFF;
> }
>
> - if (static_call(kvm_x86_get_cpl)(vcpu) != 0) {
> - ret = -KVM_EPERM;
> - goto out;
> - }
> -
> ret = -KVM_ENOSYS;
>
> switch (nr) {
> @@ -8475,6 +8459,35 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> ret = -KVM_ENOSYS;
> break;
> }
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(__kvm_emulate_hypercall);
> +
> +int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
> +{
> + unsigned long nr, a0, a1, a2, a3, ret;
> + int op_64_bit;
> +
> + if (kvm_xen_hypercall_enabled(vcpu->kvm))
> + return kvm_xen_hypercall(vcpu);
> +
> + if (kvm_hv_hypercall_enabled(vcpu))
> + return kvm_hv_hypercall(vcpu);
> +
> + nr = kvm_rax_read(vcpu);
> + a0 = kvm_rbx_read(vcpu);
> + a1 = kvm_rcx_read(vcpu);
> + a2 = kvm_rdx_read(vcpu);
> + a3 = kvm_rsi_read(vcpu);
> +
> + op_64_bit = is_64_bit_mode(vcpu);
> +
> + if (static_call(kvm_x86_get_cpl)(vcpu) != 0) {
> + ret = -KVM_EPERM;
> + goto out;
> + }
> +
> + ret = __kvm_emulate_hypercall(vcpu, nr, a0, a1, a2, a3, op_64_bit);
> out:
> if (!op_64_bit)
> ret = (u32)ret;
>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

\
 
 \ /
  Last update: 2021-07-06 15:41    [W:0.740 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site