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Date: Mon, 1 Apr 2013 17:56:44 +0800 From: Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com> To: mtosatti@...hat.com Cc: gleb@...hat.com, linux-kernel@...r.kernel.org, kvm@...r.kernel.org, Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com> Subject: [PATCH v2 1/6] KVM: MMU: retain more available bits on mmio spte Let mmio spte only use bit62 and bit63 on upper 32 bits, then bit 52 ~ bit 61 can be used for other purposes Signed-off-by: Xiao Guangrong <xiaoguangrong@...ux.vnet.ibm.com> --- arch/x86/kvm/vmx.c | 4 ++-- arch/x86/kvm/x86.c | 8 +++++++- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 03f5746..915ef56 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3983,10 +3983,10 @@ static void ept_set_mmio_spte_mask(void) /* * EPT Misconfigurations can be generated if the value of bits 2:0 * of an EPT paging-structure entry is 110b (write/execute). - * Also, magic bits (0xffull << 49) is set to quickly identify mmio + * Also, magic bits (0x3ull << 62) is set to quickly identify mmio * spte. */ - kvm_mmu_set_mmio_spte_mask(0xffull << 49 | 0x6ull); + kvm_mmu_set_mmio_spte_mask((0x3ull << 62) | 0x6ull); } /* diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9ce99ed..12ad5b5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5194,7 +5194,13 @@ static void kvm_set_mmio_spte_mask(void) * Set the reserved bits and the present bit of an paging-structure * entry to generate page fault with PFER.RSV = 1. */ - mask = ((1ull << (62 - maxphyaddr + 1)) - 1) << maxphyaddr; + /* Mask the reserved physical address bits. */ + mask = ((1ull << (51 - maxphyaddr + 1)) - 1) << maxphyaddr; + + /* Bit 62 is always reserved for 32bit host. */ + mask |= 0x3ull << 62; + + /* Set the present bit. */ mask |= 1ull; #ifdef CONFIG_X86_64 -- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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