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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2013-06-07 16:51:23 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2013-06-20 23:33:20 +0200 |
| commit | 885032b91042288f98d3888c2aaf3a108d348d5c (patch) | |
| tree | 3f51f6eca75275a2be2a2cf19be546bc6ec27855 /arch/x86/kvm/x86.c | |
| parent | 87d41fb4da6467622b7a87fd6afe8071abab6dae (diff) | |
| download | lwn-885032b91042288f98d3888c2aaf3a108d348d5c.tar.gz lwn-885032b91042288f98d3888c2aaf3a108d348d5c.zip | |
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@linux.vnet.ibm.com>
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 737c804b310c..15cf34d4ae95 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5280,7 +5280,13 @@ 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 |