From 7321f47eada53a395fb3086d49297eebb19e8e58 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 22 Feb 2022 16:46:41 +0100 Subject: [PATCH] KVM: x86: hyper-v: Fix the maximum number of sparse banks for XMM fast TLB flush hypercalls When TLB flush hypercalls (HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX are issued in 'XMM fast' mode, the maximum number of allowed sparse_banks is not 'HV_HYPERCALL_MAX_XMM_REGISTERS - 1' (5) but twice as many (10) as each XMM register is 128 bit long and can hold two 64 bit long banks. Cc: stable@vger.kernel.org # 5.14.x Fixes: 5974565bc26d ("KVM: x86: kvm_hv_flush_tlb use inputs from XMM registers") Signed-off-by: Vitaly Kuznetsov Message-Id: <20220222154642.684285-4-vkuznets@redhat.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/hyperv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index c28a268..8f07b13 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1819,7 +1819,8 @@ static u64 kvm_hv_flush_tlb(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc) if (!all_cpus) { if (hc->fast) { - if (sparse_banks_len > HV_HYPERCALL_MAX_XMM_REGISTERS - 1) + /* XMM0 is already consumed, each XMM holds two sparse banks. */ + if (sparse_banks_len > 2 * (HV_HYPERCALL_MAX_XMM_REGISTERS - 1)) return HV_STATUS_INVALID_HYPERCALL_INPUT; for (i = 0; i < sparse_banks_len; i += 2) { sparse_banks[i] = sse128_lo(hc->xmm[i / 2 + 1]); -- 2.7.4