From b5fcc59be72a76b5cf7bcc6d4aba6cdb14557d44 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Sat, 7 Jan 2023 01:10:23 +0000 Subject: [PATCH] KVM: x86: Split out logic to generate "readable" APIC regs mask to helper Move the generation of the readable APIC regs bitmask to a standalone helper so that VMX can use the mask for its MSR interception bitmaps. No functional change intended. Reviewed-by: Maxim Levitsky Link: https://lore.kernel.org/r/20230107011025.565472-5-seanjc@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/lapic.c | 34 +++++++++++++++++++++------------- arch/x86/kvm/lapic.h | 2 ++ 2 files changed, 23 insertions(+), 13 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 91e6f958d4b2..d2ad5e8b63a4 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1561,12 +1561,9 @@ static inline struct kvm_lapic *to_lapic(struct kvm_io_device *dev) #define APIC_REGS_MASK(first, count) \ (APIC_REG_MASK(first) * ((1ull << (count)) - 1)) -static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, - void *data) +u64 kvm_lapic_readable_reg_mask(struct kvm_lapic *apic) { - unsigned char alignment = offset & 0xf; - u32 result; - /* this bitmask has a bit cleared for each reserved register */ + /* Leave bits '0' for reserved and write-only registers. */ u64 valid_reg_mask = APIC_REG_MASK(APIC_ID) | APIC_REG_MASK(APIC_LVR) | @@ -1592,22 +1589,33 @@ static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, if (kvm_lapic_lvt_supported(apic, LVT_CMCI)) valid_reg_mask |= APIC_REG_MASK(APIC_LVTCMCI); - /* - * ARBPRI, DFR, and ICR2 are not valid in x2APIC mode. WARN if KVM - * reads ICR in x2APIC mode as it's an 8-byte register in x2APIC and - * needs to be manually handled by the caller. - */ + /* ARBPRI, DFR, and ICR2 are not valid in x2APIC mode. */ if (!apic_x2apic_mode(apic)) valid_reg_mask |= APIC_REG_MASK(APIC_ARBPRI) | APIC_REG_MASK(APIC_DFR) | APIC_REG_MASK(APIC_ICR2); - else - WARN_ON_ONCE(offset == APIC_ICR); + + return valid_reg_mask; +} +EXPORT_SYMBOL_GPL(kvm_lapic_readable_reg_mask); + +static int kvm_lapic_reg_read(struct kvm_lapic *apic, u32 offset, int len, + void *data) +{ + unsigned char alignment = offset & 0xf; + u32 result; + + /* + * WARN if KVM reads ICR in x2APIC mode, as it's an 8-byte register in + * x2APIC and needs to be manually handled by the caller. + */ + WARN_ON_ONCE(apic_x2apic_mode(apic) && offset == APIC_ICR); if (alignment + len > 4) return 1; - if (offset > 0x3f0 || !(valid_reg_mask & APIC_REG_MASK(offset))) + if (offset > 0x3f0 || + !(kvm_lapic_readable_reg_mask(apic) & APIC_REG_MASK(offset))) return 1; result = __apic_read(apic, offset & ~0xf); diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h index df316ede7546..0a0ea4b5dd8c 100644 --- a/arch/x86/kvm/lapic.h +++ b/arch/x86/kvm/lapic.h @@ -146,6 +146,8 @@ int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data); int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len); void kvm_lapic_exit(void); +u64 kvm_lapic_readable_reg_mask(struct kvm_lapic *apic); + #define VEC_POS(v) ((v) & (32 - 1)) #define REG_POS(v) (((v) >> 5) << 4) -- 2.25.1