diff options
author | Bandan Das <bsd@redhat.com> | 2014-04-21 15:20:14 -0400 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2014-04-28 11:14:51 +0200 |
commit | fe2b201b3be91575857227da7ef21f661bc460b1 (patch) | |
tree | dd1d04f0273b4cdc23d3882395e31e0d2ed4c4c2 /arch/x86/kvm | |
parent | e8e249d78e0600cb892c87992b6c8c9ea3b301ae (diff) | |
download | linux-fe2b201b3be91575857227da7ef21f661bc460b1.tar.bz2 |
KVM: x86: Check for host supported fields in shadow vmcs
We track shadow vmcs fields through two static lists,
one for read only and another for r/w fields. However, with
addition of new vmcs fields, not all fields may be supported on
all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on
unsupported hosts will result in a vmwrite error. For example, commit
36be0b9deb23161 introduced GUEST_BNDCFGS, which is not supported
by all processors. Filter out host unsupported fields before
letting guests use shadow vmcs
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r-- | arch/x86/kvm/vmx.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 1f68c5831924..33e8c028842f 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -503,7 +503,7 @@ static inline struct vcpu_vmx *to_vmx(struct kvm_vcpu *vcpu) [number##_HIGH] = VMCS12_OFFSET(name)+4 -static const unsigned long shadow_read_only_fields[] = { +static unsigned long shadow_read_only_fields[] = { /* * We do NOT shadow fields that are modified when L0 * traps and emulates any vmx instruction (e.g. VMPTRLD, @@ -526,10 +526,10 @@ static const unsigned long shadow_read_only_fields[] = { GUEST_LINEAR_ADDRESS, GUEST_PHYSICAL_ADDRESS }; -static const int max_shadow_read_only_fields = +static int max_shadow_read_only_fields = ARRAY_SIZE(shadow_read_only_fields); -static const unsigned long shadow_read_write_fields[] = { +static unsigned long shadow_read_write_fields[] = { GUEST_RIP, GUEST_RSP, GUEST_CR0, @@ -558,7 +558,7 @@ static const unsigned long shadow_read_write_fields[] = { HOST_FS_SELECTOR, HOST_GS_SELECTOR }; -static const int max_shadow_read_write_fields = +static int max_shadow_read_write_fields = ARRAY_SIZE(shadow_read_write_fields); static const unsigned short vmcs_field_to_offset_table[] = { @@ -3009,6 +3009,41 @@ static void free_kvm_area(void) } } +static void init_vmcs_shadow_fields(void) +{ + int i, j; + + /* No checks for read only fields yet */ + + for (i = j = 0; i < max_shadow_read_write_fields; i++) { + switch (shadow_read_write_fields[i]) { + case GUEST_BNDCFGS: + if (!vmx_mpx_supported()) + continue; + break; + default: + break; + } + + if (j < i) + shadow_read_write_fields[j] = + shadow_read_write_fields[i]; + j++; + } + max_shadow_read_write_fields = j; + + /* shadowed fields guest access without vmexit */ + for (i = 0; i < max_shadow_read_write_fields; i++) { + clear_bit(shadow_read_write_fields[i], + vmx_vmwrite_bitmap); + clear_bit(shadow_read_write_fields[i], + vmx_vmread_bitmap); + } + for (i = 0; i < max_shadow_read_only_fields; i++) + clear_bit(shadow_read_only_fields[i], + vmx_vmread_bitmap); +} + static __init int alloc_kvm_area(void) { int cpu; @@ -3039,6 +3074,8 @@ static __init int hardware_setup(void) enable_vpid = 0; if (!cpu_has_vmx_shadow_vmcs()) enable_shadow_vmcs = 0; + if (enable_shadow_vmcs) + init_vmcs_shadow_fields(); if (!cpu_has_vmx_ept() || !cpu_has_vmx_ept_4levels()) { @@ -8803,14 +8840,6 @@ static int __init vmx_init(void) memset(vmx_vmread_bitmap, 0xff, PAGE_SIZE); memset(vmx_vmwrite_bitmap, 0xff, PAGE_SIZE); - /* shadowed read/write fields */ - for (i = 0; i < max_shadow_read_write_fields; i++) { - clear_bit(shadow_read_write_fields[i], vmx_vmwrite_bitmap); - clear_bit(shadow_read_write_fields[i], vmx_vmread_bitmap); - } - /* shadowed read only fields */ - for (i = 0; i < max_shadow_read_only_fields; i++) - clear_bit(shadow_read_only_fields[i], vmx_vmread_bitmap); /* * Allow direct access to the PC debug port (it is often used for I/O |