linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
	Marc Zyngier <maz@kernel.org>,  Anup Patel <anup@brainfault.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Christian Borntraeger <borntraeger@linux.ibm.com>,
	Janosch Frank <frankja@linux.ibm.com>,
	 Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Nathan Chancellor <nathan@kernel.org>,
	 Nick Desaulniers <ndesaulniers@google.com>
Cc: James Morse <james.morse@arm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	 Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	 Atish Patra <atishp@atishpatra.org>,
	David Hildenbrand <david@redhat.com>, Tom Rix <trix@redhat.com>,
	 kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	 kvmarm@lists.cs.columbia.edu, kvm-riscv@lists.infradead.org,
	 linux-riscv@lists.infradead.org, llvm@lists.linux.dev,
	 linux-kernel@vger.kernel.org,
	Colton Lewis <coltonlewis@google.com>,
	 Peter Gonda <pgonda@google.com>,
	Andrew Jones <andrew.jones@linux.dev>,
	 Sean Christopherson <seanjc@google.com>
Subject: [PATCH v5 2/7] KVM: selftests: Consolidate boilerplate code in get_ucall()
Date: Thu, 25 Aug 2022 23:25:17 +0000	[thread overview]
Message-ID: <20220825232522.3997340-3-seanjc@google.com> (raw)
In-Reply-To: <20220825232522.3997340-1-seanjc@google.com>

Consolidate the actual copying of a ucall struct from guest=>host into
the common get_ucall().  Return a host virtual address instead of a guest
virtual address even though the addr_gva2hva() part could be moved to
get_ucall() too.  Conceptually, get_ucall() is invoked from the host and
should return a host virtual address (and returning NULL for "nothing to
see here" is far superior to returning 0).

Use pointer shenanigans instead of an unnecessary bounce buffer when the
caller of get_ucall() provides a valid pointer.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 .../selftests/kvm/include/ucall_common.h      |  8 ++------
 .../testing/selftests/kvm/lib/aarch64/ucall.c | 14 +++-----------
 tools/testing/selftests/kvm/lib/riscv/ucall.c | 19 +++----------------
 tools/testing/selftests/kvm/lib/s390x/ucall.c | 16 +++-------------
 .../testing/selftests/kvm/lib/ucall_common.c  | 19 +++++++++++++++++++
 .../testing/selftests/kvm/lib/x86_64/ucall.c  | 16 +++-------------
 6 files changed, 33 insertions(+), 59 deletions(-)

diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h
index 5a85f5318bbe..63bfc60be995 100644
--- a/tools/testing/selftests/kvm/include/ucall_common.h
+++ b/tools/testing/selftests/kvm/include/ucall_common.h
@@ -27,9 +27,10 @@ struct ucall {
 void ucall_arch_init(struct kvm_vm *vm, void *arg);
 void ucall_arch_uninit(struct kvm_vm *vm);
 void ucall_arch_do_ucall(vm_vaddr_t uc);
-uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc);
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu);
 
 void ucall(uint64_t cmd, int nargs, ...);
+uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc);
 
 static inline void ucall_init(struct kvm_vm *vm, void *arg)
 {
@@ -41,11 +42,6 @@ static inline void ucall_uninit(struct kvm_vm *vm)
 	ucall_arch_uninit(vm);
 }
 
-static inline uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
-{
-	return ucall_arch_get_ucall(vcpu, uc);
-}
-
 #define GUEST_SYNC_ARGS(stage, arg1, arg2, arg3, arg4)	\
 				ucall(UCALL_SYNC, 6, "hello", stage, arg1, arg2, arg3, arg4)
 #define GUEST_SYNC(stage)	ucall(UCALL_SYNC, 2, "hello", stage)
diff --git a/tools/testing/selftests/kvm/lib/aarch64/ucall.c b/tools/testing/selftests/kvm/lib/aarch64/ucall.c
index 3630708c32d6..f214f5cc53d3 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/ucall.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/ucall.c
@@ -75,13 +75,9 @@ void ucall_arch_do_ucall(vm_vaddr_t uc)
 	WRITE_ONCE(*ucall_exit_mmio_addr, uc);
 }
 
-uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	struct ucall ucall = {};
-
-	if (uc)
-		memset(uc, 0, sizeof(*uc));
 
 	if (run->exit_reason == KVM_EXIT_MMIO &&
 	    run->mmio.phys_addr == (uint64_t)ucall_exit_mmio_addr) {
@@ -90,12 +86,8 @@ uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
 		TEST_ASSERT(run->mmio.is_write && run->mmio.len == 8,
 			    "Unexpected ucall exit mmio address access");
 		memcpy(&gva, run->mmio.data, sizeof(gva));
-		memcpy(&ucall, addr_gva2hva(vcpu->vm, gva), sizeof(ucall));
-
-		vcpu_run_complete_io(vcpu);
-		if (uc)
-			memcpy(uc, &ucall, sizeof(ucall));
+		return addr_gva2hva(vcpu->vm, gva);
 	}
 
-	return ucall.cmd;
+	return NULL;
 }
diff --git a/tools/testing/selftests/kvm/lib/riscv/ucall.c b/tools/testing/selftests/kvm/lib/riscv/ucall.c
index b1598f418c1f..37e091d4366e 100644
--- a/tools/testing/selftests/kvm/lib/riscv/ucall.c
+++ b/tools/testing/selftests/kvm/lib/riscv/ucall.c
@@ -51,27 +51,15 @@ void ucall_arch_do_ucall(vm_vaddr_t uc)
 		  uc, 0, 0, 0, 0, 0);
 }
 
-uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	struct ucall ucall = {};
-
-	if (uc)
-		memset(uc, 0, sizeof(*uc));
 
 	if (run->exit_reason == KVM_EXIT_RISCV_SBI &&
 	    run->riscv_sbi.extension_id == KVM_RISCV_SELFTESTS_SBI_EXT) {
 		switch (run->riscv_sbi.function_id) {
 		case KVM_RISCV_SELFTESTS_SBI_UCALL:
-			memcpy(&ucall,
-			       addr_gva2hva(vcpu->vm, run->riscv_sbi.args[0]),
-			       sizeof(ucall));
-
-			vcpu_run_complete_io(vcpu);
-			if (uc)
-				memcpy(uc, &ucall, sizeof(ucall));
-
-			break;
+			return addr_gva2hva(vcpu->vm, run->riscv_sbi.args[0]);
 		case KVM_RISCV_SELFTESTS_SBI_UNEXP:
 			vcpu_dump(stderr, vcpu, 2);
 			TEST_ASSERT(0, "Unexpected trap taken by guest");
@@ -80,6 +68,5 @@ uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
 			break;
 		}
 	}
-
-	return ucall.cmd;
+	return NULL;
 }
diff --git a/tools/testing/selftests/kvm/lib/s390x/ucall.c b/tools/testing/selftests/kvm/lib/s390x/ucall.c
index 114cb4af295f..0f695a031d35 100644
--- a/tools/testing/selftests/kvm/lib/s390x/ucall.c
+++ b/tools/testing/selftests/kvm/lib/s390x/ucall.c
@@ -20,13 +20,9 @@ void ucall_arch_do_ucall(vm_vaddr_t uc)
 	asm volatile ("diag 0,%0,0x501" : : "a"(uc) : "memory");
 }
 
-uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	struct ucall ucall = {};
-
-	if (uc)
-		memset(uc, 0, sizeof(*uc));
 
 	if (run->exit_reason == KVM_EXIT_S390_SIEIC &&
 	    run->s390_sieic.icptcode == 4 &&
@@ -34,13 +30,7 @@ uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
 	    (run->s390_sieic.ipb >> 16) == 0x501) {
 		int reg = run->s390_sieic.ipa & 0xf;
 
-		memcpy(&ucall, addr_gva2hva(vcpu->vm, run->s.regs.gprs[reg]),
-		       sizeof(ucall));
-
-		vcpu_run_complete_io(vcpu);
-		if (uc)
-			memcpy(uc, &ucall, sizeof(ucall));
+		return addr_gva2hva(vcpu->vm, run->s.regs.gprs[reg]);
 	}
-
-	return ucall.cmd;
+	return NULL;
 }
diff --git a/tools/testing/selftests/kvm/lib/ucall_common.c b/tools/testing/selftests/kvm/lib/ucall_common.c
index 2395c7f1d543..ced480860746 100644
--- a/tools/testing/selftests/kvm/lib/ucall_common.c
+++ b/tools/testing/selftests/kvm/lib/ucall_common.c
@@ -18,3 +18,22 @@ void ucall(uint64_t cmd, int nargs, ...)
 
 	ucall_arch_do_ucall((vm_vaddr_t)&uc);
 }
+
+uint64_t get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+{
+	struct ucall ucall;
+	void *addr;
+
+	if (!uc)
+		uc = &ucall;
+
+	addr = ucall_arch_get_ucall(vcpu);
+	if (addr) {
+		memcpy(uc, addr, sizeof(*uc));
+		vcpu_run_complete_io(vcpu);
+	} else {
+		memset(uc, 0, sizeof(*uc));
+	}
+
+	return uc->cmd;
+}
diff --git a/tools/testing/selftests/kvm/lib/x86_64/ucall.c b/tools/testing/selftests/kvm/lib/x86_64/ucall.c
index 9f532dba1003..ead9946399ab 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/ucall.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/ucall.c
@@ -22,25 +22,15 @@ void ucall_arch_do_ucall(vm_vaddr_t uc)
 		: : [port] "d" (UCALL_PIO_PORT), "D" (uc) : "rax", "memory");
 }
 
-uint64_t ucall_arch_get_ucall(struct kvm_vcpu *vcpu, struct ucall *uc)
+void *ucall_arch_get_ucall(struct kvm_vcpu *vcpu)
 {
 	struct kvm_run *run = vcpu->run;
-	struct ucall ucall = {};
-
-	if (uc)
-		memset(uc, 0, sizeof(*uc));
 
 	if (run->exit_reason == KVM_EXIT_IO && run->io.port == UCALL_PIO_PORT) {
 		struct kvm_regs regs;
 
 		vcpu_regs_get(vcpu, &regs);
-		memcpy(&ucall, addr_gva2hva(vcpu->vm, (vm_vaddr_t)regs.rdi),
-		       sizeof(ucall));
-
-		vcpu_run_complete_io(vcpu);
-		if (uc)
-			memcpy(uc, &ucall, sizeof(ucall));
+		return addr_gva2hva(vcpu->vm, regs.rdi);
 	}
-
-	return ucall.cmd;
+	return NULL;
 }
-- 
2.37.2.672.g94769d06f0-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2022-08-25 23:26 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-25 23:25 [PATCH v5 0/7] KVM: selftests: Implement ucall "pool" (for SEV) Sean Christopherson
2022-08-25 23:25 ` [PATCH v5 1/7] KVM: selftests: Consolidate common code for populating ucall struct Sean Christopherson
2022-08-25 23:25 ` Sean Christopherson [this message]
2022-08-25 23:25 ` [PATCH v5 3/7] KVM: selftests: Automatically do init_ucall() for non-barebones VMs Sean Christopherson
2022-08-29 16:15   ` Andrew Jones
2022-08-25 23:25 ` [PATCH v5 4/7] tools: Add atomic_test_and_set_bit() Sean Christopherson
2022-08-25 23:25 ` [PATCH v5 5/7] KVM: selftests: Make arm64's MMIO ucall multi-VM friendly Sean Christopherson
2022-08-29 16:19   ` Andrew Jones
2022-08-25 23:25 ` [PATCH v5 6/7] KVM: selftest: Drop now-unnecessary ucall_uninit() Sean Christopherson
2022-08-29 16:21   ` Andrew Jones
2022-08-25 23:25 ` [PATCH v5 7/7] KVM: selftests: Add ucall pool based implementation Sean Christopherson
2022-08-29 16:36   ` Andrew Jones
2022-08-30  4:27     ` Sean Christopherson
2022-08-26 21:32 ` [PATCH v5 0/7] KVM: selftests: Implement ucall "pool" (for SEV) Peter Gonda

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220825232522.3997340-3-seanjc@google.com \
    --to=seanjc@google.com \
    --cc=alexandru.elisei@arm.com \
    --cc=andrew.jones@linux.dev \
    --cc=anup@brainfault.org \
    --cc=aou@eecs.berkeley.edu \
    --cc=atishp@atishpatra.org \
    --cc=borntraeger@linux.ibm.com \
    --cc=coltonlewis@google.com \
    --cc=david@redhat.com \
    --cc=frankja@linux.ibm.com \
    --cc=imbrenda@linux.ibm.com \
    --cc=james.morse@arm.com \
    --cc=kvm-riscv@lists.infradead.org \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=llvm@lists.linux.dev \
    --cc=maz@kernel.org \
    --cc=nathan@kernel.org \
    --cc=ndesaulniers@google.com \
    --cc=oliver.upton@linux.dev \
    --cc=palmer@dabbelt.com \
    --cc=paul.walmsley@sifive.com \
    --cc=pbonzini@redhat.com \
    --cc=pgonda@google.com \
    --cc=suzuki.poulose@arm.com \
    --cc=trix@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).