From 01630ab8543f21df30b0dca19087b85744f61aee Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 12 May 2017 11:04:52 +0100 Subject: ARM: KVM: Fix tracepoint generation after move to virt/kvm/arm/ Moving most of the shared code to virt/kvm/arm had for consequence that KVM/ARM doesn't build anymore, because the code that used to define the tracepoints is now somewhere else. Fix this by defining CREATE_TRACE_POINTS in coproc.c, and clean-up trace.h as well. Fixes: 35d2d5d490e2 ("KVM: arm/arm64: Move shared files to virt/kvm/arm") Reported-by: Arnd Bergmann Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall --- arch/arm/kvm/coproc.c | 1 + arch/arm/kvm/trace.h | 8 ++++---- 2 files changed, 5 insertions(+), 4 deletions(-) (limited to 'arch') diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 2c14b69511e9..ac8d36da4d08 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -32,6 +32,7 @@ #include #include "../vfp/vfpinstr.h" +#define CREATE_TRACE_POINTS #include "trace.h" #include "coproc.h" diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h index fc0943776db2..b0d10648c486 100644 --- a/arch/arm/kvm/trace.h +++ b/arch/arm/kvm/trace.h @@ -1,5 +1,5 @@ -#if !defined(_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ) -#define _TRACE_KVM_H +#if !defined(_TRACE_ARM_KVM_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_ARM_KVM_H #include @@ -74,10 +74,10 @@ TRACE_EVENT(kvm_hvc, __entry->vcpu_pc, __entry->r0, __entry->imm) ); -#endif /* _TRACE_KVM_H */ +#endif /* _TRACE_ARM_KVM_H */ #undef TRACE_INCLUDE_PATH -#define TRACE_INCLUDE_PATH arch/arm/kvm +#define TRACE_INCLUDE_PATH . #undef TRACE_INCLUDE_FILE #define TRACE_INCLUDE_FILE trace -- cgit v1.2.3 From cde13b5dad60471886a3bccb4f4134c647c4a9dc Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 2 May 2017 14:30:37 +0100 Subject: arm64: KVM: Do not use stack-protector to compile EL2 code We like living dangerously. Nothing explicitely forbids stack-protector to be used in the EL2 code, while distributions routinely compile their kernel with it. We're just lucky that no code actually triggers the instrumentation. Let's not try our luck for much longer, and disable stack-protector for code living at EL2. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm64/kvm/hyp/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index aaf42ae8d8c3..14c4e3b14bcb 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -2,6 +2,8 @@ # Makefile for Kernel-based Virtual Machine module, HYP part # +ccflags-y += -fno-stack-protector + KVM=../../../../virt/kvm obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v2-sr.o -- cgit v1.2.3 From 501ad27c67ed0b90df465f23d33e9aed64058a47 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 2 May 2017 14:30:38 +0100 Subject: arm: KVM: Do not use stack-protector to compile HYP code We like living dangerously. Nothing explicitely forbids stack-protector to be used in the HYP code, while distributions routinely compile their kernel with it. We're just lucky that no code actually triggers the instrumentation. Let's not try our luck for much longer, and disable stack-protector for code living at HYP. Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier Acked-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/kvm/hyp/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile index 3023bb530edf..8679405b0b2b 100644 --- a/arch/arm/kvm/hyp/Makefile +++ b/arch/arm/kvm/hyp/Makefile @@ -2,6 +2,8 @@ # Makefile for Kernel-based Virtual Machine module, HYP part # +ccflags-y += -fno-stack-protector + KVM=../../../../virt/kvm obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v2-sr.o -- cgit v1.2.3 From 661e6b02b5aa82db31897f36e96324b77450fd7a Mon Sep 17 00:00:00 2001 From: Zhichao Huang Date: Thu, 11 May 2017 13:46:11 +0100 Subject: KVM: arm: plug potential guest hardware debug leakage MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hardware debugging in guests is not intercepted currently, it means that a malicious guest can bring down the entire machine by writing to the debug registers. This patch enable trapping of all debug registers, preventing the guests to access the debug registers. This includes access to the debug mode(DBGDSCR) in the guest world all the time which could otherwise mess with the host state. Reads return 0 and writes are ignored (RAZ_WI). The result is the guest cannot detect any working hardware based debug support. As debug exceptions are still routed to the guest normal debug using software based breakpoints still works. To support debugging using hardware registers we need to implement a debug register aware world switch as well as special trapping for registers that may affect the host state. Cc: stable@vger.kernel.org Signed-off-by: Zhichao Huang Signed-off-by: Alex Bennée Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- arch/arm/include/asm/kvm_coproc.h | 3 +- arch/arm/kvm/coproc.c | 77 ++++++++++++++++++++++++++++++--------- arch/arm/kvm/handle_exit.c | 4 +- arch/arm/kvm/hyp/switch.c | 4 +- 4 files changed, 66 insertions(+), 22 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/kvm_coproc.h b/arch/arm/include/asm/kvm_coproc.h index 4917c2f7e459..e74ab0fbab79 100644 --- a/arch/arm/include/asm/kvm_coproc.h +++ b/arch/arm/include/asm/kvm_coproc.h @@ -31,7 +31,8 @@ void kvm_register_target_coproc_table(struct kvm_coproc_target_table *table); int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_handle_cp_0_13_access(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run); -int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run); +int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run); +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run); int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run); diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index ac8d36da4d08..1403ffb1916b 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -112,12 +112,6 @@ int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run) return 1; } -int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run) -{ - kvm_inject_undefined(vcpu); - return 1; -} - static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r) { /* @@ -533,12 +527,7 @@ static int emulate_cp15(struct kvm_vcpu *vcpu, return 1; } -/** - * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access - * @vcpu: The VCPU pointer - * @run: The kvm_run struct - */ -int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) +static struct coproc_params decode_64bit_hsr(struct kvm_vcpu *vcpu) { struct coproc_params params; @@ -552,9 +541,38 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) params.Rt2 = (kvm_vcpu_get_hsr(vcpu) >> 10) & 0xf; params.CRm = 0; + return params; +} + +/** + * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct coproc_params params = decode_64bit_hsr(vcpu); + return emulate_cp15(vcpu, ¶ms); } +/** + * kvm_handle_cp14_64 -- handles a mrrc/mcrr trap on a guest CP14 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct coproc_params params = decode_64bit_hsr(vcpu); + + /* raz_wi cp14 */ + pm_fake(vcpu, ¶ms, NULL); + + /* handled */ + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); + return 1; +} + static void reset_coproc_regs(struct kvm_vcpu *vcpu, const struct coproc_reg *table, size_t num) { @@ -565,12 +583,7 @@ static void reset_coproc_regs(struct kvm_vcpu *vcpu, table[i].reset(vcpu, &table[i]); } -/** - * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access - * @vcpu: The VCPU pointer - * @run: The kvm_run struct - */ -int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) +static struct coproc_params decode_32bit_hsr(struct kvm_vcpu *vcpu) { struct coproc_params params; @@ -584,9 +597,37 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) params.Op2 = (kvm_vcpu_get_hsr(vcpu) >> 17) & 0x7; params.Rt2 = 0; + return params; +} + +/** + * kvm_handle_cp15_32 -- handles a mrc/mcr trap on a guest CP15 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct coproc_params params = decode_32bit_hsr(vcpu); return emulate_cp15(vcpu, ¶ms); } +/** + * kvm_handle_cp14_32 -- handles a mrc/mcr trap on a guest CP14 access + * @vcpu: The VCPU pointer + * @run: The kvm_run struct + */ +int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + struct coproc_params params = decode_32bit_hsr(vcpu); + + /* raz_wi cp14 */ + pm_fake(vcpu, ¶ms, NULL); + + /* handled */ + kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); + return 1; +} + /****************************************************************************** * Userspace API *****************************************************************************/ diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c index 5fd7968cdae9..f86a9aaef462 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -95,9 +95,9 @@ static exit_handle_fn arm_exit_handlers[] = { [HSR_EC_WFI] = kvm_handle_wfx, [HSR_EC_CP15_32] = kvm_handle_cp15_32, [HSR_EC_CP15_64] = kvm_handle_cp15_64, - [HSR_EC_CP14_MR] = kvm_handle_cp14_access, + [HSR_EC_CP14_MR] = kvm_handle_cp14_32, [HSR_EC_CP14_LS] = kvm_handle_cp14_load_store, - [HSR_EC_CP14_64] = kvm_handle_cp14_access, + [HSR_EC_CP14_64] = kvm_handle_cp14_64, [HSR_EC_CP_0_13] = kvm_handle_cp_0_13_access, [HSR_EC_CP10_ID] = kvm_handle_cp10_id, [HSR_EC_HVC] = handle_hvc, diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c index 92678b7bd046..624a510d31df 100644 --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -48,7 +48,9 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu, u32 *fpexc_host) write_sysreg(HSTR_T(15), HSTR); write_sysreg(HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11), HCPTR); val = read_sysreg(HDCR); - write_sysreg(val | HDCR_TPM | HDCR_TPMCR, HDCR); + val |= HDCR_TPM | HDCR_TPMCR; /* trap performance monitors */ + val |= HDCR_TDRA | HDCR_TDOSA | HDCR_TDA; /* trap debug regs */ + write_sysreg(val, HDCR); } static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) -- cgit v1.2.3 From 9b619a8f08da9f61f166edbbe30ad05c359ec19e Mon Sep 17 00:00:00 2001 From: Zhichao Huang Date: Thu, 11 May 2017 13:46:12 +0100 Subject: KVM: arm: rename pm_fake handler to trap_raz_wi MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit pm_fake doesn't quite describe what the handler does (ignoring writes and returning 0 for reads). As we're about to use it (a lot) in a different context, rename it with a (admitedly cryptic) name that make sense for all users. Signed-off-by: Zhichao Huang Reviewed-by: Alex Bennee Acked-by: Christoffer Dall Acked-by: Marc Zyngier Signed-off-by: Alex Bennée Signed-off-by: Christoffer Dall --- arch/arm/kvm/coproc.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) (limited to 'arch') diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c index 1403ffb1916b..6d1d2e26dfe5 100644 --- a/arch/arm/kvm/coproc.c +++ b/arch/arm/kvm/coproc.c @@ -279,7 +279,7 @@ static bool access_gic_sre(struct kvm_vcpu *vcpu, * must always support PMCCNTR (the cycle counter): we just RAZ/WI for * all PM registers, which doesn't crash the guest kernel at least. */ -static bool pm_fake(struct kvm_vcpu *vcpu, +static bool trap_raz_wi(struct kvm_vcpu *vcpu, const struct coproc_params *p, const struct coproc_reg *r) { @@ -289,19 +289,19 @@ static bool pm_fake(struct kvm_vcpu *vcpu, return read_zero(vcpu, p); } -#define access_pmcr pm_fake -#define access_pmcntenset pm_fake -#define access_pmcntenclr pm_fake -#define access_pmovsr pm_fake -#define access_pmselr pm_fake -#define access_pmceid0 pm_fake -#define access_pmceid1 pm_fake -#define access_pmccntr pm_fake -#define access_pmxevtyper pm_fake -#define access_pmxevcntr pm_fake -#define access_pmuserenr pm_fake -#define access_pmintenset pm_fake -#define access_pmintenclr pm_fake +#define access_pmcr trap_raz_wi +#define access_pmcntenset trap_raz_wi +#define access_pmcntenclr trap_raz_wi +#define access_pmovsr trap_raz_wi +#define access_pmselr trap_raz_wi +#define access_pmceid0 trap_raz_wi +#define access_pmceid1 trap_raz_wi +#define access_pmccntr trap_raz_wi +#define access_pmxevtyper trap_raz_wi +#define access_pmxevcntr trap_raz_wi +#define access_pmuserenr trap_raz_wi +#define access_pmintenset trap_raz_wi +#define access_pmintenclr trap_raz_wi /* Architected CP15 registers. * CRn denotes the primary register number, but is copied to the CRm in the @@ -566,7 +566,7 @@ int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run) struct coproc_params params = decode_64bit_hsr(vcpu); /* raz_wi cp14 */ - pm_fake(vcpu, ¶ms, NULL); + trap_raz_wi(vcpu, ¶ms, NULL); /* handled */ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); @@ -621,7 +621,7 @@ int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run) struct coproc_params params = decode_32bit_hsr(vcpu); /* raz_wi cp14 */ - pm_fake(vcpu, ¶ms, NULL); + trap_raz_wi(vcpu, ¶ms, NULL); /* handled */ kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu)); -- cgit v1.2.3