>From ad6033048d498baba7889ae0e14788c92d4baacb Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Thu, 7 Apr 2022 09:52:46 -0700 Subject: [PATCH] KVM: x86: hyper-v: Add helper to read hypercall data for arrary 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: Sean Christopherson --- arch/x86/kvm/hyperv.c | 53 +++++++++++++++++++++++++++---------------- 1 file changed, 33 insertions(+), 20 deletions(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index e4f381b46a28..58e7aff6057a 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1782,38 +1782,51 @@ 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) + +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) { - 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); + /* + * 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 inline int hv_tlb_flush_ring_free(struct kvm_vcpu_hv *hv_vcpu, @@ -1952,7 +1965,7 @@ 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; @@ -2063,7 +2076,7 @@ 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; base-commit: 9e28f2680fd1606225ab456bb28d30598110a520 -- 2.35.1.1178.g4f1659d476-goog