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From: Marc Zyngier <maz@kernel.org>
To: linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: Andre Przywara <andre.przywara@arm.com>,
	Christoffer Dall <christoffer.dall@arm.com>,
	Jintack Lim <jintack@cs.columbia.edu>,
	Haibo Xu <haibo.xu@linaro.org>, James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	kernel-team@android.com
Subject: [PATCH v4 58/66] KVM: arm64: Map VNCR-capable registers to a separate page
Date: Mon, 10 May 2021 17:59:12 +0100	[thread overview]
Message-ID: <20210510165920.1913477-59-maz@kernel.org> (raw)
In-Reply-To: <20210510165920.1913477-1-maz@kernel.org>

With ARMv8.4-NV, registers that can be directly accessed in memory
by the guest have to live at architected offsets in a special page.

Let's annotate the sysreg enum to reflect the offset at which they
are in this page, whith a little twist:

If running on HW that doesn't have the ARMv8.4-NV feature, or even
a VM that doesn't use NV, we store all the system registers in the
usual sys_regs array. The only difference with the pre-8.4
situation is that VNCR-capable registers are at a "similar" offset
as in the VNCR page (we can compute the actual offset at compile
time), and that the sys_regs array is both bigger and sparse.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h | 97 ++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 34 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index b382c317ec5a..815ae39f7857 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -27,6 +27,7 @@
 #include <asm/kvm.h>
 #include <asm/kvm_asm.h>
 #include <asm/thread_info.h>
+#include <asm/vncr_mapping.h>
 
 #define __KVM_HAVE_ARCH_INTC_INITIALIZED
 
@@ -171,31 +172,32 @@ struct kvm_vcpu_fault_info {
 	u64 disr_el1;		/* Deferred [SError] Status Register */
 };
 
+/*
+ * VNCR() just places the VNCR_capable registers in the enum after
+ * __VNCR_START__, and the value (after correction) to be an 8-byte offset
+ * from the VNCR base. As we don't require the enum to be otherwise ordered,
+ * we need the terrible hack below to ensure that we correctly size the
+ * sys_regs array, no matter what.
+ *
+ * The __MAX__ macro has been lifted from Sean Eron Anderson's wonderful
+ * treasure trove of bit hacks:
+ * https://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ */
+#define __MAX__(x,y)	((x) ^ (((x) ^ (y)) & -((x) < (y))))
+#define VNCR(r)						\
+	__before_##r,					\
+	r = __VNCR_START__ + ((VNCR_ ## r) / 8),	\
+	__after_##r = __MAX__(__before_##r - 1, r)
+
 enum vcpu_sysreg {
 	__INVALID_SYSREG__,   /* 0 is reserved as an invalid value */
 	MPIDR_EL1,	/* MultiProcessor Affinity Register */
 	CSSELR_EL1,	/* Cache Size Selection Register */
-	SCTLR_EL1,	/* System Control Register */
-	ACTLR_EL1,	/* Auxiliary Control Register */
-	CPACR_EL1,	/* Coprocessor Access Control */
-	ZCR_EL1,	/* SVE Control */
-	TTBR0_EL1,	/* Translation Table Base Register 0 */
-	TTBR1_EL1,	/* Translation Table Base Register 1 */
-	TCR_EL1,	/* Translation Control Register */
-	ESR_EL1,	/* Exception Syndrome Register */
-	AFSR0_EL1,	/* Auxiliary Fault Status Register 0 */
-	AFSR1_EL1,	/* Auxiliary Fault Status Register 1 */
-	FAR_EL1,	/* Fault Address Register */
-	MAIR_EL1,	/* Memory Attribute Indirection Register */
-	VBAR_EL1,	/* Vector Base Address Register */
-	CONTEXTIDR_EL1,	/* Context ID Register */
 	TPIDR_EL0,	/* Thread ID, User R/W */
 	TPIDRRO_EL0,	/* Thread ID, User R/O */
 	TPIDR_EL1,	/* Thread ID, Privileged */
-	AMAIR_EL1,	/* Aux Memory Attribute Indirection Register */
 	CNTKCTL_EL1,	/* Timer Control Register (EL1) */
 	PAR_EL1,	/* Physical Address Register */
-	MDSCR_EL1,	/* Monitor Debug System Control Register */
 	MDCCINT_EL1,	/* Monitor Debug Comms Channel Interrupt Enable Reg */
 	DISR_EL1,	/* Deferred Interrupt Status Register */
 
@@ -226,16 +228,6 @@ enum vcpu_sysreg {
 	APGAKEYLO_EL1,
 	APGAKEYHI_EL1,
 
-	ELR_EL1,
-	SP_EL1,
-	SPSR_EL1,
-
-	CNTVOFF_EL2,
-	CNTV_CVAL_EL0,
-	CNTV_CTL_EL0,
-	CNTP_CVAL_EL0,
-	CNTP_CTL_EL0,
-
 	/* 32bit specific registers. */
 	DACR32_EL2,	/* Domain Access Control Register */
 	IFSR32_EL2,	/* Instruction Fault Status Register */
@@ -243,20 +235,14 @@ enum vcpu_sysreg {
 	DBGVCR32_EL2,	/* Debug Vector Catch Register */
 
 	/* EL2 registers */
-	VPIDR_EL2,	/* Virtualization Processor ID Register */
-	VMPIDR_EL2,	/* Virtualization Multiprocessor ID Register */
 	SCTLR_EL2,	/* System Control Register (EL2) */
 	ACTLR_EL2,	/* Auxiliary Control Register (EL2) */
-	HCR_EL2,	/* Hypervisor Configuration Register */
 	MDCR_EL2,	/* Monitor Debug Configuration Register (EL2) */
 	CPTR_EL2,	/* Architectural Feature Trap Register (EL2) */
-	HSTR_EL2,	/* Hypervisor System Trap Register */
 	HACR_EL2,	/* Hypervisor Auxiliary Control Register */
 	TTBR0_EL2,	/* Translation Table Base Register 0 (EL2) */
 	TTBR1_EL2,	/* Translation Table Base Register 1 (EL2) */
 	TCR_EL2,	/* Translation Control Register (EL2) */
-	VTTBR_EL2,	/* Virtualization Translation Table Base Register */
-	VTCR_EL2,	/* Virtualization Translation Control Register */
 	SPSR_EL2,	/* EL2 saved program status register */
 	ELR_EL2,	/* EL2 exception link register */
 	AFSR0_EL2,	/* Auxiliary Fault Status Register 0 (EL2) */
@@ -269,7 +255,6 @@ enum vcpu_sysreg {
 	VBAR_EL2,	/* Vector Base Address Register (EL2) */
 	RVBAR_EL2,	/* Reset Vector Base Address Register */
 	CONTEXTIDR_EL2,	/* Context ID Register (EL2) */
-	TPIDR_EL2,	/* EL2 Software Thread ID Register */
 	CNTHCTL_EL2,	/* Counter-timer Hypervisor Control register */
 	SP_EL2,		/* EL2 Stack Pointer */
 	CNTHP_CTL_EL2,
@@ -277,6 +262,41 @@ enum vcpu_sysreg {
 	CNTHV_CTL_EL2,
 	CNTHV_CVAL_EL2,
 
+	__VNCR_START__,	/* Any VNCR-capable reg goes after this point */
+
+	VNCR(SCTLR_EL1),/* System Control Register */
+	VNCR(ACTLR_EL1),/* Auxiliary Control Register */
+	VNCR(CPACR_EL1),/* Coprocessor Access Control */
+	VNCR(ZCR_EL1),	/* SVE Control */
+	VNCR(TTBR0_EL1),/* Translation Table Base Register 0 */
+	VNCR(TTBR1_EL1),/* Translation Table Base Register 1 */
+	VNCR(TCR_EL1),	/* Translation Control Register */
+	VNCR(ESR_EL1),	/* Exception Syndrome Register */
+	VNCR(AFSR0_EL1),/* Auxiliary Fault Status Register 0 */
+	VNCR(AFSR1_EL1),/* Auxiliary Fault Status Register 1 */
+	VNCR(FAR_EL1),	/* Fault Address Register */
+	VNCR(MAIR_EL1),	/* Memory Attribute Indirection Register */
+	VNCR(VBAR_EL1),	/* Vector Base Address Register */
+	VNCR(CONTEXTIDR_EL1),	/* Context ID Register */
+	VNCR(AMAIR_EL1),/* Aux Memory Attribute Indirection Register */
+	VNCR(MDSCR_EL1),/* Monitor Debug System Control Register */
+	VNCR(ELR_EL1),
+	VNCR(SP_EL1),
+	VNCR(SPSR_EL1),
+	VNCR(VPIDR_EL2),/* Virtualization Processor ID Register */
+	VNCR(VMPIDR_EL2),/* Virtualization Multiprocessor ID Register */
+	VNCR(HCR_EL2),	/* Hypervisor Configuration Register */
+	VNCR(HSTR_EL2),	/* Hypervisor System Trap Register */
+	VNCR(VTTBR_EL2),/* Virtualization Translation Table Base Register */
+	VNCR(VTCR_EL2),	/* Virtualization Translation Control Register */
+	VNCR(TPIDR_EL2),/* EL2 Software Thread ID Register */
+
+	VNCR(CNTVOFF_EL2),
+	VNCR(CNTV_CVAL_EL0),
+	VNCR(CNTV_CTL_EL0),
+	VNCR(CNTP_CVAL_EL0),
+	VNCR(CNTP_CTL_EL0),
+
 	NR_SYS_REGS	/* Nothing after this line! */
 };
 
@@ -293,6 +313,9 @@ struct kvm_cpu_context {
 	u64 sys_regs[NR_SYS_REGS];
 
 	struct kvm_vcpu *__hyp_running_vcpu;
+
+	/* This pointer has to be 4kB aligned. */
+	u64 *vncr_array;
 };
 
 struct kvm_pmu_events {
@@ -520,7 +543,13 @@ struct kvm_vcpu_arch {
  * for system registers that are never context switched, but only
  * emulated.
  */
-#define __ctxt_sys_reg(c,r)	(&(c)->sys_regs[(r)])
+static inline u64 *__ctxt_sys_reg(const struct kvm_cpu_context *ctxt, int r)
+{
+	if (unlikely(r >= __VNCR_START__ && ctxt->vncr_array))
+		return &ctxt->vncr_array[r - __VNCR_START__];
+
+	return (u64 *)&ctxt->sys_regs[r];
+}
 
 #define ctxt_sys_reg(c,r)	(*__ctxt_sys_reg(c,r))
 
-- 
2.29.2


  parent reply	other threads:[~2021-05-10 17:29 UTC|newest]

Thread overview: 75+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 16:58 [PATCH v4 00/66] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 01/66] arm64: Add ARM64_HAS_NESTED_VIRT cpufeature Marc Zyngier
2021-05-20 13:32   ` Zenghui Yu
2021-05-10 16:58 ` [PATCH v4 02/66] KVM: arm64: nv: Introduce nested virtualization VCPU feature Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 03/66] KVM: arm64: nv: Reset VCPU to EL2 registers if VCPU nested virt is set Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 04/66] KVM: arm64: nv: Allow userspace to set PSR_MODE_EL2x Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 05/66] KVM: arm64: nv: Add EL2 system registers to vcpu context Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 06/66] KVM: arm64: nv: Add nested virt VCPU primitives for vEL2 VCPU state Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 07/66] KVM: arm64: nv: Handle HCR_EL2.NV system register traps Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 08/66] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 09/66] KVM: arm64: nv: Support virtual EL2 exceptions Marc Zyngier
2021-05-20 12:55   ` Zenghui Yu
2021-05-10 16:58 ` [PATCH v4 10/66] KVM: arm64: nv: Inject HVC exceptions to the virtual EL2 Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 11/66] KVM: arm64: nv: Handle trapped ERET from " Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 12/66] KVM: arm64: nv: Add non-VHE-EL2->EL1 translation helpers Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 13/66] KVM: arm64: nv: Handle virtual EL2 registers in vcpu_read/write_sys_reg() Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 14/66] KVM: arm64: nv: Handle SPSR_EL2 specially Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 15/66] KVM: arm64: nv: Handle HCR_EL2.E2H specially Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 16/66] KVM: arm64: nv: Save/Restore vEL2 sysregs Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 17/66] KVM: arm64: nv: Emulate PSTATE.M for a guest hypervisor Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 18/66] KVM: arm64: nv: Trap EL1 VM register accesses in virtual EL2 Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 19/66] KVM: arm64: nv: Trap SPSR_EL1, ELR_EL1 and VBAR_EL1 from " Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 20/66] KVM: arm64: nv: Trap CPACR_EL1 access in " Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 21/66] KVM: arm64: nv: Handle PSCI call via smc from the guest Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 22/66] KVM: arm64: nv: Respect virtual HCR_EL2.TWX setting Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 23/66] KVM: arm64: nv: Respect virtual CPTR_EL2.{TFP,FPEN} settings Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 24/66] KVM: arm64: nv: Respect the virtual HCR_EL2.NV bit setting Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 25/66] KVM: arm64: nv: Respect virtual HCR_EL2.TVM and TRVM settings Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 26/66] KVM: arm64: nv: Respect the virtual HCR_EL2.NV1 bit setting Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 27/66] KVM: arm64: nv: Emulate EL12 register accesses from the virtual EL2 Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 28/66] KVM: arm64: nv: Forward debug traps to the nested guest Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 29/66] KVM: arm64: nv: Configure HCR_EL2 for nested virtualization Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 30/66] KVM: arm64: nv: Only toggle cache for virtual EL2 when SCTLR_EL2 changes Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 31/66] KVM: arm64: nv: Filter out unsupported features from ID regs Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 32/66] KVM: arm64: nv: Hide RAS from nested guests Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 33/66] KVM: arm64: nv: Support multiple nested Stage-2 mmu structures Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 34/66] KVM: arm64: nv: Implement nested Stage-2 page table walk logic Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 35/66] KVM: arm64: nv: Handle shadow stage 2 page faults Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 36/66] KVM: arm64: nv: Restrict S2 RD/WR permissions to match the guest's Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 37/66] KVM: arm64: nv: Unmap/flush shadow stage 2 page tables Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 38/66] KVM: arm64: nv: Introduce sys_reg_desc.forward_trap Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 39/66] KVM: arm64: nv: Set a handler for the system instruction traps Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 40/66] KVM: arm64: nv: Trap and emulate AT instructions from virtual EL2 Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 41/66] KVM: arm64: nv: Trap and emulate TLBI " Marc Zyngier
2021-07-14 16:40   ` Chase Conklin
2021-11-29 18:12     ` Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 42/66] KVM: arm64: nv: Fold guest's HCR_EL2 configuration into the host's Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 43/66] KVM: arm64: nv: arch_timer: Support hyp timer emulation Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 44/66] KVM: arm64: nv: Add handling of EL2-specific timer registers Marc Zyngier
2021-05-10 16:58 ` [PATCH v4 45/66] KVM: arm64: nv: Load timer before the GIC Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 46/66] KVM: arm64: nv: Nested GICv3 Support Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 47/66] KVM: arm64: nv: Don't load the GICv4 context on entering a nested guest Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 48/66] KVM: arm64: nv: vgic: Emulate the HW bit in software Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 49/66] KVM: arm64: nv: vgic: Allow userland to set VGIC maintenance IRQ Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 50/66] KVM: arm64: nv: Implement maintenance interrupt forwarding Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 51/66] KVM: arm64: nv: Add nested GICv3 tracepoints Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 52/66] KVM: arm64: nv: Allow userspace to request KVM_ARM_VCPU_NESTED_VIRT Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 53/66] KVM: arm64: nv: Add handling of ARMv8.4-TTL TLB invalidation Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 54/66] KVM: arm64: nv: Invalidate TLBs based on shadow S2 TTL-like information Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 55/66] KVM: arm64: Allow populating S2 SW bits Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 56/66] KVM: arm64: nv: Tag shadow S2 entries with nested level Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 57/66] KVM: arm64: nv: Add include containing the VNCR_EL2 offsets Marc Zyngier
2021-05-10 16:59 ` Marc Zyngier [this message]
2021-05-10 16:59 ` [PATCH v4 59/66] KVM: arm64: nv: Move nested vgic state into the sysreg file Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 60/66] KVM: arm64: Add ARMv8.4 Enhanced Nested Virt cpufeature Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 61/66] KVM: arm64: nv: Synchronize PSTATE early on exit Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 62/66] KVM: arm64: nv: Sync nested timer state with ARMv8.4 Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 63/66] KVM: arm64: nv: Allocate VNCR page when required Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 64/66] KVM: arm64: nv: Enable ARMv8.4-NV support Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 65/66] KVM: arm64: nv: Fast-track 'InHost' exception returns Marc Zyngier
2021-05-10 16:59 ` [PATCH v4 66/66] KVM: arm64: nv: Fast-track EL1 TLBIs for VHE guests Marc Zyngier
2021-06-03  7:07 ` [PATCH v4 00/66] KVM: arm64: ARMv8.3/8.4 Nested Virtualization support Jamie Iles
2021-06-03  8:39   ` Marc Zyngier
2021-06-03 11:08     ` Marc Zyngier
2021-06-07  9:59     ` Jamie Iles

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