On Wed, Aug 22, 2018 at 04:53:00PM +0200, Paolo Bonzini wrote:
Two bug fixes:
- missing entries in the l1d_param array; this can cause a host crash
if an access attempts to reach the missing entry. Future-proof the get function against any overflows as well. However, the two entries VMENTER_L1D_FLUSH_EPT_DISABLED and VMENTER_L1D_FLUSH_NOT_REQUIRED must not be accepted by the parse function, so disable them there.
- invalid values must be rejected even if the CPU does not have the
bug, so test for them before checking boot_cpu_has(X86_BUG_L1TF)
... and a small refactoring, since the .cmd field is redundant with the index in the array.
Reported-by: Bandan Das bsd@redhat.com Cc: stable@vger.kernel.org Fixes: a7b9020b06ec6d7c3f3b0d4ef1a9eba12654f4f7 Signed-off-by: Paolo Bonzini pbonzini@redhat.com
Reviewed-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com
with one little nitpick
arch/x86/kvm/vmx.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index c76ca8c4befa..8dae47e7267a 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -198,12 +198,14 @@ static const struct { const char *option;
- enum vmx_l1d_flush_state cmd;
- bool for_parse;
} vmentry_l1d_param[] = {
- {"auto", VMENTER_L1D_FLUSH_AUTO},
- {"never", VMENTER_L1D_FLUSH_NEVER},
- {"cond", VMENTER_L1D_FLUSH_COND},
- {"always", VMENTER_L1D_FLUSH_ALWAYS},
- [VMENTER_L1D_FLUSH_AUTO] = {"auto", true},
- [VMENTER_L1D_FLUSH_NEVER] = {"never", true},
- [VMENTER_L1D_FLUSH_COND] = {"cond", true},
- [VMENTER_L1D_FLUSH_ALWAYS] = {"always", true},
- [VMENTER_L1D_FLUSH_EPT_DISABLED] = {"EPT disabled", false},
- [VMENTER_L1D_FLUSH_NOT_REQUIRED] = {"not required", false},
Ingo likes these to have tabs. Any chance you could do:
[VMENTER_L1D_FLUSH_NOT_REQUIRED] = {"not required", false},
or so?
}; #define L1D_CACHE_ORDER 4 @@ -287,8 +289,9 @@ static int vmentry_l1d_flush_parse(const char *s) if (s) { for (i = 0; i < ARRAY_SIZE(vmentry_l1d_param); i++) {
if (sysfs_streq(s, vmentry_l1d_param[i].option))return vmentry_l1d_param[i].cmd;
if (vmentry_l1d_param[i].for_parse &&sysfs_streq(s, vmentry_l1d_param[i].option))return i;@@ -298,13 +301,13 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) { int l1tf, ret;
- if (!boot_cpu_has(X86_BUG_L1TF))
return 0;- l1tf = vmentry_l1d_flush_parse(s); if (l1tf < 0) return l1tf;
- if (!boot_cpu_has(X86_BUG_L1TF))
return 0;- /*
- Has vmx_init() run already? If not then this is the pre init
- parameter parsing. In that case just store the value and let
@@ -324,6 +327,9 @@ static int vmentry_l1d_flush_set(const char *s, const struct kernel_param *kp) static int vmentry_l1d_flush_get(char *s, const struct kernel_param *kp) {
- if (WARN_ON_ONCE(l1tf_vmx_mitigation >= ARRAY_SIZE(vmentry_l1d_param)))
return sprintf(s, "???\n");- return sprintf(s, "%s\n", vmentry_l1d_param[l1tf_vmx_mitigation].option);
} -- 1.8.3.1