Signed-off-by: Eugene Korenevsky <ekorenevsky@xxxxxxxxx>
---
Notes:
This patch adds checks on Guest RIP specified in Intel Software Developer Manual.
The following checks are performed on processors that support Intel 64 architecture:
- Bits 63:32 must be 0 if the "IA-32e mode guest" VM-entry control is 0 or if
the L bit (bit 13) in the access-rights field for CS is 0.
- If the processor supports N < 64 linear-address bits, bits 63:N must be identical
if the "IA-32e mode guest" VM-entry control is 1 and the L bit in the access-rights
field for CS is 1. (No check applies if the processor supports 64 linear-address
bits.)
arch/x86/kvm/vmx.c | 27 ++++++++++++++++++++++++++-
1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6a951d8..e2da83b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3828,6 +3828,28 @@ static bool cs_ss_rpl_check(struct kvm_vcpu *vcpu)
(ss.selector & SELECTOR_RPL_MASK));
}
+#ifdef CONFIG_X86_64
+static bool rip_valid(struct kvm_vcpu *vcpu)
+{
+ unsigned long rip;
+ struct kvm_segment cs;
+ bool longmode;
+
+ /* RIP must be canonical in long mode
+ * Bits 63:32 of RIP must be zero in other processor modes */
+ longmode = false;
+ if (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE) {
+ vmx_get_segment(vcpu, &cs, VCPU_SREG_CS);
+ longmode = (cs.l != 0);
+ }
+ rip = kvm_register_read(vcpu, VCPU_REGS_RIP);
+ if (longmode)
+ return !is_noncanonical_address(rip);
+ else
+ return (rip >> 32) == 0;
+}
+#endif
+
/*
* Check if guest state is valid. Returns true if valid, false if
* not.
@@ -3873,8 +3895,11 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu)
if (!ldtr_valid(vcpu))
return false;
}
+#ifdef CONFIG_X86_64
+ if (!rip_valid(vcpu))
+ return false;
+#endif
/* TODO:
- * - Add checks on RIP
* - Add checks on RFLAGS
*/
--
2.0.4
--
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