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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2012-08-21 11:02:51 +0800 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2012-08-22 15:09:03 +0300 |
| commit | 4d8b81abc47b83a1939e59df2fdb0e98dfe0eedd (patch) | |
| tree | 47ea77cb4f77a2884a0478ecf84f62e32e5661ee /arch/x86 | |
| parent | 7068d0971524dd47a38f44f6020ba133432871ca (diff) | |
| download | op-kernel-dev-4d8b81abc47b83a1939e59df2fdb0e98dfe0eedd.zip op-kernel-dev-4d8b81abc47b83a1939e59df2fdb0e98dfe0eedd.tar.gz | |
KVM: introduce readonly memslot
In current code, if we map a readonly memory space from host to guest
and the page is not currently mapped in the host, we will get a fault
pfn and async is not allowed, then the vm will crash
We introduce readonly memory region to map ROM/ROMD to the guest, read access
is happy for readonly memslot, write access on readonly memslot will cause
KVM_EXIT_MMIO exit
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu.c | 9 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 1 |
3 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h index 246617e..521bf25 100644 --- a/arch/x86/include/asm/kvm.h +++ b/arch/x86/include/asm/kvm.h @@ -25,6 +25,7 @@ #define __KVM_HAVE_DEBUGREGS #define __KVM_HAVE_XSAVE #define __KVM_HAVE_XCRS +#define __KVM_HAVE_READONLY_MEM /* Architectural interrupt line count. */ #define KVM_NR_INTERRUPTS 256 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 5548971..8e312a2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2647,6 +2647,15 @@ static void kvm_send_hwpoison_signal(unsigned long address, struct task_struct * static int kvm_handle_bad_page(struct kvm_vcpu *vcpu, gfn_t gfn, pfn_t pfn) { + /* + * Do not cache the mmio info caused by writing the readonly gfn + * into the spte otherwise read access on readonly gfn also can + * caused mmio page fault and treat it as mmio access. + * Return 1 to tell kvm to emulate it. + */ + if (pfn == KVM_PFN_ERR_RO_FAULT) + return 1; + if (pfn == KVM_PFN_ERR_HWPOISON) { kvm_send_hwpoison_signal(gfn_to_hva(vcpu->kvm, gfn), current); return 0; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 704680d..42bbf41 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2175,6 +2175,7 @@ int kvm_dev_ioctl_check_extension(long ext) case KVM_CAP_GET_TSC_KHZ: case KVM_CAP_PCI_2_3: case KVM_CAP_KVMCLOCK_CTRL: + case KVM_CAP_READONLY_MEM: r = 1; break; case KVM_CAP_COALESCED_MMIO: |
