[PULL 19/30] target/arm: Implement FEAT_HAFDBS, dirty bit portion

Maintainers: "Cédric Le Goater" <clg@kaod.org>, Peter Maydell <peter.maydell@linaro.org>, Andrew Jeffery <andrew@aj.id.au>, Joel Stanley <joel@jms.id.au>, Richard Henderson <richard.henderson@linaro.org>, Helge Deller <deller@gmx.de>, Sergio Lopez <slp@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Eduardo Habkost <eduardo@habkost.net>, Laurent Vivier <laurent@vivier.eu>, Paul Burton <paulburton@kernel.org>, Aleksandar Rikalo <aleksandar.rikalo@syrmia.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Stafford Horne <shorne@gmail.com>, BALATON Zoltan <balaton@eik.bme.hu>, Daniel Henrique Barboza <danielhb413@gmail.com>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Palmer Dabbelt <palmer@dabbelt.com>, Alistair Francis <alistair.francis@wdc.com>, Bin Meng <bin.meng@windriver.com>, Yoshinori Sato <ysato@users.sourceforge.jp>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Cornelia Huck <cohuck@redhat.com>, Thomas Huth <thuth@redhat.com>, David Hildenbrand <david@redhat.com>, Yanan Wang <wangyanan55@huawei.com>, Juan Quintela <quintela@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>
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[PULL 19/30] target/arm: Implement FEAT_HAFDBS, dirty bit portion
Posted by Peter Maydell 2 years, 5 months ago
From: Richard Henderson <richard.henderson@linaro.org>

Perform the atomic update for hardware management of the dirty bit.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221024051851.3074715-14-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu64.c |  2 +-
 target/arm/ptw.c   | 16 ++++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index f2c3e41f5a7..3d74f134f57 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -1165,7 +1165,7 @@ static void aarch64_max_initfn(Object *obj)
     cpu->isar.id_aa64mmfr0 = t;
 
     t = cpu->isar.id_aa64mmfr1;
-    t = FIELD_DP64(t, ID_AA64MMFR1, HAFDBS, 1);   /* FEAT_HAFDBS, AF only */
+    t = FIELD_DP64(t, ID_AA64MMFR1, HAFDBS, 2);   /* FEAT_HAFDBS */
     t = FIELD_DP64(t, ID_AA64MMFR1, VMIDBITS, 2); /* FEAT_VMID16 */
     t = FIELD_DP64(t, ID_AA64MMFR1, VH, 1);       /* FEAT_VHE */
     t = FIELD_DP64(t, ID_AA64MMFR1, HPDS, 1);     /* FEAT_HPDS */
diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index 03776f47a01..6b8f14fb3cd 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -1444,6 +1444,22 @@ static bool get_phys_addr_lpae(CPUARMState *env, S1Translate *ptw,
                 goto do_fault;
             }
         }
+
+        /*
+         * Dirty Bit.
+         * If HD is enabled, pre-emptively set/clear the appropriate AP/S2AP
+         * bit for writeback. The actual write protection test may still be
+         * overridden by tableattrs, to be merged below.
+         */
+        if (param.hd
+            && extract64(descriptor, 51, 1)  /* DBM */
+            && access_type == MMU_DATA_STORE) {
+            if (regime_is_stage2(mmu_idx)) {
+                new_descriptor |= 1ull << 7;    /* set S2AP[1] */
+            } else {
+                new_descriptor &= ~(1ull << 7); /* clear AP[2] */
+            }
+        }
     }
 
     /*
-- 
2.25.1