From 951f9fd74f2d826fff1d84a8ec34b491517dc15d Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Wed, 23 Sep 2015 10:34:26 +0200 Subject: [PATCH] KVM: x86: manually unroll bad_mt_xwr loop The loop is computing one of two constants, it can be simpler to write everything inline. Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c3f39aa..b8482c0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3706,7 +3706,7 @@ static void __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, int maxphyaddr, bool execonly) { - int pte; + u64 bad_mt_xwr; rsvd_check->rsvd_bits_mask[0][3] = rsvd_bits(maxphyaddr, 51) | rsvd_bits(3, 7); @@ -3724,14 +3724,16 @@ __reset_rsvds_bits_mask_ept(struct rsvd_bits_validate *rsvd_check, rsvd_bits(maxphyaddr, 51) | rsvd_bits(12, 20); rsvd_check->rsvd_bits_mask[1][0] = rsvd_check->rsvd_bits_mask[0][0]; - for (pte = 0; pte < 64; pte++) { - int rwx_bits = pte & 7; - int mt = pte >> 3; - if (mt == 0x2 || mt == 0x3 || mt == 0x7 || - rwx_bits == 0x2 || rwx_bits == 0x6 || - (rwx_bits == 0x4 && !execonly)) - rsvd_check->bad_mt_xwr |= (1ull << pte); + bad_mt_xwr = 0xFFull << (2 * 8); /* bits 3..5 must not be 2 */ + bad_mt_xwr |= 0xFFull << (3 * 8); /* bits 3..5 must not be 3 */ + bad_mt_xwr |= 0xFFull << (7 * 8); /* bits 3..5 must not be 7 */ + bad_mt_xwr |= REPEAT_BYTE(1ull << 2); /* bits 0..2 must not be 010 */ + bad_mt_xwr |= REPEAT_BYTE(1ull << 6); /* bits 0..2 must not be 110 */ + if (!execonly) { + /* bits 0..2 must not be 100 unless VMX capabilities allow it */ + bad_mt_xwr |= REPEAT_BYTE(1ull << 4); } + rsvd_check->bad_mt_xwr = bad_mt_xwr; } static void reset_rsvds_bits_mask_ept(struct kvm_vcpu *vcpu, -- 2.7.4