Commit 56b5354f authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
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KVM: x86: hyper-v: Add helper to read hypercall data for array 



Move the guts of kvm_get_sparse_vp_set() to a helper so that the code for
reading a guest-provided array can be reused in the future, e.g. for
getting a list of virtual addresses whose TLB entries need to be flushed.

Opportunisticaly swap the order of the data and XMM adjustment so that
the XMM/gpa offsets are bundled together.

No functional change intended.

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Message-Id: <20221101145426.251680-11-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 0823570f

arch/x86/kvm/hyperv.c

+33 −20
Original line number Diff line number Diff line
@@ -1753,38 +1753,51 @@ struct kvm_hv_hcall { 
	sse128_t xmm[HV_HYPERCALL_MAX_XMM_REGISTERS];

};



static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,

				 int consumed_xmm_halves,

				 u64 *sparse_banks, gpa_t offset)

{

	u16 var_cnt;

	int i;



	if (hc->var_cnt > 64)

		return -EINVAL;



	/* Ignore banks that cannot possibly contain a legal VP index. */

	var_cnt = min_t(u16, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS);

static int kvm_hv_get_hc_data(struct kvm *kvm, struct kvm_hv_hcall *hc,

			      u16 orig_cnt, u16 cnt_cap, u64 *data,

			      int consumed_xmm_halves, gpa_t offset)

{

	/*

	 * Preserve the original count when ignoring entries via a "cap", KVM

	 * still needs to validate the guest input (though the non-XMM path

	 * punts on the checks).

	 */

	u16 cnt = min(orig_cnt, cnt_cap);

	int i, j;



	if (hc->fast) {

		/*

		 * Each XMM holds two sparse banks, but do not count halves that

		 * have already been consumed for hypercall parameters.

		 */

		if (hc->var_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - consumed_xmm_halves)

		if (orig_cnt > 2 * HV_HYPERCALL_MAX_XMM_REGISTERS - consumed_xmm_halves)

			return HV_STATUS_INVALID_HYPERCALL_INPUT;

		for (i = 0; i < var_cnt; i++) {

			int j = i + consumed_xmm_halves;



		for (i = 0; i < cnt; i++) {

			j = i + consumed_xmm_halves;

			if (j % 2)

				sparse_banks[i] = sse128_hi(hc->xmm[j / 2]);

				data[i] = sse128_hi(hc->xmm[j / 2]);

			else

				sparse_banks[i] = sse128_lo(hc->xmm[j / 2]);

				data[i] = sse128_lo(hc->xmm[j / 2]);

		}

		return 0;

	}



	return kvm_read_guest(kvm, hc->ingpa + offset, sparse_banks,

			      var_cnt * sizeof(*sparse_banks));

	return kvm_read_guest(kvm, hc->ingpa + offset, data,

			      cnt * sizeof(*data));

}



static u64 kvm_get_sparse_vp_set(struct kvm *kvm, struct kvm_hv_hcall *hc,

				 u64 *sparse_banks, int consumed_xmm_halves,

				 gpa_t offset)

{

	if (hc->var_cnt > 64)

		return -EINVAL;



	/* Cap var_cnt to ignore banks that cannot contain a legal VP index. */

	return kvm_hv_get_hc_data(kvm, hc, hc->var_cnt, KVM_HV_MAX_SPARSE_VCPU_SET_BITS,

				  sparse_banks, consumed_xmm_halves, offset);

}



static void hv_tlb_flush_enqueue(struct kvm_vcpu *vcpu)
@@ -1895,7 +1908,7 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) 
		if (!hc->var_cnt)

			goto ret_success;



		if (kvm_get_sparse_vp_set(kvm, hc, 2, sparse_banks,

		if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 2,

					  offsetof(struct hv_tlb_flush_ex,

						   hv_vp_set.bank_contents)))

			return HV_STATUS_INVALID_HYPERCALL_INPUT;
@@ -2006,7 +2019,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) 
		if (!hc->var_cnt)

			goto ret_success;



		if (kvm_get_sparse_vp_set(kvm, hc, 1, sparse_banks,

		if (kvm_get_sparse_vp_set(kvm, hc, sparse_banks, 1,

					  offsetof(struct hv_send_ipi_ex,

						   vp_set.bank_contents)))

			return HV_STATUS_INVALID_HYPERCALL_INPUT;