linux-kernel - [PATCH] KVM: x86: Skip pae_root shadow allocation if tdp enabled

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Date:   Wed, 25 Jul 2018 16:32:14 +0800
From:   Liang Chen <liangchen.linux@...il.com>
To:     pbonzini@...hat.com
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Liang Chen <liangchen.linux@...il.com>
Subject: [PATCH] KVM: x86: Skip pae_root shadow allocation if tdp enabled

Considering the fact that the pae_root shadow is not needed when
tdp is in use, skip the pae_root shadow page allocation to allow
mmu creation even not being able to obtain memory from DMA32
zone when particular cgroup cpuset.mems or mempolicy control is
applied.

Signed-off-by: Liang Chen <liangchen.linux@...il.com>
---
 arch/x86/kvm/mmu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index d594690..af8cc1e 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -5029,6 +5029,9 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
 	struct page *page;
 	int i;
 
+	if (tdp_enabled)
+		return 0;
+
 	/*
 	 * When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
 	 * Therefore we need to allocate shadow page tables in the first
-- 
1.8.3.1