lkml.org 
[lkml]   [2021]   [Jul]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC PATCH v2 14/69] KVM: x86: Split core of hypercall emulation to helper function
    Date
    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;
    --
    2.25.1
    \
     
     \ /
      Last update: 2021-07-03 00:08    [W:2.356 / U:0.004 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site